INTRODUCTION
THE FIRST GREEK PHILOSOPHERS asked, “What is everything made of?”, which is the fundamental question of metaphysics. This prompted further inquiries into the structure of the cosmos, and also raised more abstract questions about the nature of existence itself – the branch of metaphysics known as ontology. Over the centuries, philosophers have offered many different answers to these questions, inspiring different approaches, and schools of thought. Some, for example, argued that the universe is made up of a single substance – a view known as “monism” – while others proposed that the universe has two component elements – a view known as “dualism”. Similarly, some regarded the universe to be eternal and immutable, while others thought that it is constantly changing.
These contrasting views were the subject of philosophical debate, which gave rise to yet more questions: how can we know anything about the world? How do we acquire our knowledge? These questions are the topic of epistemology, or the theory of knowledge. According to some philosophers, known as “rationalists”, knowledge comes from our ability to think; for others, known as “empiricists”, our primary source of knowledge is observation. In turn, these theories raise questions about the nature of human understanding, and even of thought itself.
Historically, the rationalist school can be traced back to Plato, who argued that our senses are unreliable, but that the truth can be arrived at through rational reflection. This idea was revived in the 17th century by René Descartes, Baruch Spinoza, and Gottfried Leibniz. Empiricism, on the other hand, can be traced back to Aristotle, who claimed that our senses alone can be trusted. In the modern age, this idea was revived by John Locke, George Berkeley, and David Hume – Hume even claiming that our belief in causation, for example, is unjustified. For Immanual Kant, this took scepticism too far. He proposed instead that we gain knowledge through perception, but that the world we perceive is already shaped by concepts that we are born with. This synthesis of rationalism and empiricism inspired the idealism of Georg Hegel – a monist who argued that history is driven by the evolution of ideas.
Karl Marx, an admirer of Hegel’s, subverted this idea, arguing that economic conditions, rather than ideas, are the driving force of history. At the same time, Friedrich Nietzsche argued a far more radical idea – that objective truth itself is an illusion. He claimed that the very idea of “the truth” is a hangover from our religious past, and that without it there are simply “perspectives”, or individual points of view. His claim that “God is dead” left a challenge for subsequent philosophers: to search for new foundations, or to learn to live without them.
The source of everything
The origins of Western philosophy lie in the ideas of the so-called Milesian school, a group of thinkers led by Thales of Miletus in the Greek province of Ionia (part of present-day Turkey).
Seeking rational explanations
Thales (c.624–c.546 BCE) and the other Ionian philosophers – including Anaximander and Anaximenes (c.585–c.528 BCE) – were the first thinkers known to have questioned the previously accepted mythological explanations of the nature of the cosmos. Instead, they looked to nature itself, using reason and observation to fathom the natural world, thus paving the way for future scientific and philosophical thought.
Often referred to as the “first philosopher”, Thales was also a celebrated astronomer, engineer, and statesman. His enquiries led him to believe that everything in the world, the whole of nature, is derived from a single source – what Aristotle later described as its arche, its fundamental nature or principle. This, he reasoned, must be a single material substance from which everything else in the cosmos is derived. Thales eventually concluded that this single substance must be water. His argument was based on observations: water is a vital resource, necessary for all forms of life, and all living things are moist; it is capable of changing from liquid to solid to gas, so all matter must be water in some stage of transformation; the Earth (it seemed at the time) floats on a sea of water; and moist substances become air and earth as they dry out. While he is often cited as stating “everything is water”, it would be more accurate to say that he held water to be the fundamental source of everything.
✔ PRACTICAL ENQUIRIES
Gifted with a practical mind, Thales applied intellectual rigour to philosophy and geometry. He is credited with the discovery that the height of a pyramid can be determined by measuring its shadow. Once a day, a person’s shadow is exactly the same length as their height. Thales noted that if a pyramid’s shadow is also measured at this critical moment, the height of the pyramid is revealed.
The four elements
The ancient Greeks believed that the world was made up of four elements – earth, water, air, and fire – to which Aristotle added a fifth, the “quintessence”. These elements roughly correspond to our modern understanding of the four states of matter: solid, liquid, gas, and plasma. For Thales, water was primary, and gave rise to the other elements. For Anaximenes, the primary element was air.
. Earth – Earth, and earthly things such as rock, are made of condensed water, and from this all-terrestrial life arises.
. Fire – When air is super-heated it becomes fire. Flames and lava have a life that reflects their watery origins.
. Air – Thales observed that wet things dry out in the sun and concluded that their moisture was turning into air.
. Water – Thales believed that the Earth is a disc floating on water. The shoreline is where solid ground emerges from the sea as the water condenses.
Cosmic origins
Anaximander, Thales’ student, developed an innovative theory to explain the origin and structure of the cosmos. It was radically different from the ideas of his contemporaries in Miletus.
The Boundless
Born in the Greek city of Miletus, Anaximander (c.610–546 BCE) studied with Thales, but also travelled widely, learning from Babylonian and Egyptian scholars. From his travels, he gained a knowledge of geography and astronomy that helped him to develop a strikingly original explanation of how everything had come into being. Like the other earlier Greek philosophers, he believed that there is a fundamental underlying principle, an arche, which is the source of everything in the universe. However, he rejected the idea that this is a specific material substance, such as water (as Thales believed), and instead suggested the idea of the apeiron (meaning “the Boundless”), from which everything is derived, and that the universe itself originates from a small part of the apeiron.
Anaximander describes the process of the birth of the cosmos as one of the separation of opposites, especially hot and cold, to form three concentric rings of fire, which he likened to the rims of chariot wheels. At the centre of these rings is the Earth, which is drum-shaped, like the hub of a wheel. Anaximander’s most remarkable insight is his conception of space: he realised that the heavenly bodies are not situated on a domed vault equidistant from the Earth, but that they circle the Earth at different positions in space. Perhaps even more remarkably, he reasoned that the Earth, because of its position at the centre of the cosmos, is not supported by water or any other object, but is floating freely in space.
The birth of the cosmos
Anaximander was the first thinker to offer a rational and comprehensive description of the origin of the cosmos. Based on observation, he proposed a theory that explained the behaviour of the heavenly bodies as well as the natural phenomena of the Earth.
[1] In the beginning – a small “germ” separates itself from the apeiron. This contains all the essential ingredients of the universe, including the heavenly bodies and the space they inhabit.
[2] The separation of opposites – within the “germ” that has separated from the apeiron, opposing forces, such as hot and cold, and wet and dry, begin to emerge. A cold centre forms, surrounded by vapour and an expanding sphere of fire.
[3] The sun, moon, and stars – as the ball of fire expands, it disintegrates into three concentric rings, or “wheels”, with the Earth at their centre. Light shining through holes in these opaque rings is observed as the Sun, the Moon, and the stars. The hole in the “Moon wheel” periodically closes, generating the phases of the Moon.
“What is infinite is something other than the elements, and from it the elements arise.” – Anaximander of Miletus (6th century BCE)
A drum-shaped earth: we live on the flat surface of a cylindrical Earth, floating freely in space. A central sea is surrounded by land, which in turn is surrounded by a circular ocean.
BIOLOGY
Anaximander believed that the Earth was originally covered with water, which later dried to form the land due to the heat of the Sun. The first life forms were fish-like creatures, with tough, thorny skins. This defensive covering provided a protective environment for their more valuable offspring, the first humans, who were generated to populate the land.
Sacred geometry
Perhaps the best known of the pre-Socratic philosophers, Pythagoras was a near-mythical figure who established a cult-like community devoted to the pursuit of science, mathematics, and mysticism.
A cosmos governed by numbers
Pythagoras (c.570–c.495 BCE) is remembered as the mathematician who gave his name to the theorem of right-angled triangles – that the square of the hypotenuse is equal to the sum of the squares of the other two sides. However, in his own time he was better known for his belief in the transmigration (rebirth) of the soul. Little is known of what he actually thought, since he left no written legacy, and many of the ideas ascribed to him may well be those of others. However, it is certain that he set up a community in southern Italy and trained his followers in philosophical and scientific enquiry. The “so-called Pythagoreans”, as Aristotle later described them, studied astronomy and geometry, and examined the link between numbers, mathematics, and the natural world. For example, the Pythagoreans – notably Philolaus – discovered that musical harmony is based on mathematical ratios using the first four whole numbers.
Pythagoras is believed to have learnt geometry from Thales. However, he was also familiar with the cosmological theories of the Milesian school, and Anaximander in particular, whose chief thesis was that the cosmos is formed from “the Boundless” – an inexhaustible, unobservable, life-giving substance. Pythagoras reasoned that the cosmos must have an underlying structure determined by the laws of mathematics, which imposes limits on the Boundless, giving form to the universe. For Pythagoreans, the cosmos – and everything in it – is governed by numbers, and so numbers have an almost divine significance.
“The Pythagoreans… fancied that the principles of mathematics were the principles of all things.” – Aristotle, Metaphysics (4th century BCE)
Sacred numbers
Numbers took on a mystical significance for the Pythagoreans, as they made links between mathematics and the natural world. The first four integers (whole numbers) were especially important: 1 – the fundamental number associated with the origin of everything; 2 – the material derived from it; 3 – the beginning, middle, and end; and 4 – the number of the elements. Together they add up to 10, the “perfect number”.
Geometric objects – Pythagoreans revered the number 1, from which they believed all numbers derive. For example, geometric figures can be created from a single point: connecting two points creates a line; connecting parallel lines forms a square; and connecting parallel squares creates a cube.
The octave – Pythagoras also discovered that musical intervals that sound harmonious when played together correspond to the mathematical ratios of 1:2, 2:3, and 3:4. This means that if a string sounds the note A, a string half its length will sound the A an octave higher (an eighth above); a string two-thirds its length will sound the note E (a fifth above); and a string three-quarters of its length will sound the note D (a fourth above). For Pythagoras, it was no coincidence that these ratios only involve the first four integers, which add up to the perfect number, 10.
The cosmos – Philolaus, Pythagoras’s student, is credited with the idea that all the heavenly bodies – including the Earth and a “Counter-Earth” – orbit a central fire called the Hearth. The distances of the stars and planets from the centre correspond to the ratios of the consonant musical intervals, creating what the Pythagoreans referred to as the “harmony of the spheres”.
The tetractys – The tetractys – a triangle composed of ten dots – had great symbolic significance for the Pythagoreans. Its rows of one, two, three, and four add up to the perfect number 10, and its central dot is comparable to the Hearth at the centre of the cosmos.
All is flux
While other thinkers believed the arche – the fundamental principle underlying the cosmos – to be an immutable substance, Heraclitus thought that the universe is governed by perpetual change.
The Logos
Lying at the heart of Heraclitus’s cosmology is what he calls the Logos – the reason or explanation for everything that exists. His definition of the Logos is somewhat cryptic, but it can be seen as something like the laws of nature or physics that we now know govern the universe.
Heraclitus (c.535–c.475 BCE) made a radical departure from the thinking of his contemporaries by viewing what governs the cosmos not in terms of a substance, but instead as an ongoing process of change. He observed that over time, nothing remains the same: day becomes night, seasons come and go, and living things are born and die. Everything, he concluded, is in a state of constant flux.
Heraclitus argued that it is the nature of everything to be in a process of change, and that this change is caused by a war that exists in all things. Everything is made of two contrary properties, and is characterised by both: however, over time, one of those properties becomes dominant, upsetting the former balance. Life and death, for example, are in constant strife, but also depend on each other. Heraclitus saw fire as a symbol of the Logos – always changing yet remaining uniquely itself.
✔ THE SAME RIVER
Heraclitus is famously quoted as saying that “everything flows”, likening the world to a river. The waters of a river are constantly shifting, so a person can never go into the same river twice. However, the river is also a single, unchanging entity: if its waters stop flowing, the river becomes a lake, or dries up completely.
Constant war
Heraclitus stated that all things come into being in accordance with the Logos, and consist of conflicting, opposite properties. Light and dark, life and death, hot and cold are constantly fighting for dominance. However, just as a path on a mountain is both the path up and the path down, opposites are not inherently harmful – indeed their tension sustains the world. For this reason, Heraclitus claimed that “War is the father of all things.”
All is one
Taking up a position diametrically opposed to the views of Heraclitus, Parmenides argued that the change we perceive in the world is an illusion, and that reality is eternal and unchanging.
The illusion of change
Unlike Heraclitus, Parmenides (c.515–c.450 BCE) based his ideas on logic alone as opposed to observation. Consequently, his enquiries were less concerned with what the universe is made of than the nature of being itself.
Firstly, he claims that a thing either is or is not: it either does or does not exist. Secondly, he argues it cannot be said that nothing – a void – exists, for only a thing can exist. Thirdly, he says that since there is no such thing as nothing, it is impossible for something either to come from nothing or to be reduced to nothing. From this it follows that change is impossible, for change can only ever be a particular thing (such as a seed) becoming nothing as it turns into something else (a plant) – but nothing can be reduced to nothing. What is, then, must always have been, and will always be. Strictly speaking, nothing can be said to be unlike anything else.
In contrast to this rational account of reality, the world as we perceive it seems ever-changing and impermanent. Parmenides says that this is due to the deceptive nature of our senses, and that only reason can reveal the true nature of things: a single, changeless reality in which “all is one”.
The way of truth
In his philosophical poem On Nature, Parmenides describes the world as we perceive it as the “way of opinion” – that is, the way we interpret the changes we see in the world. The “way of truth”, however, explains how the changes we see are illusions: reality is an unchanging, timeless, singular entity.
I CANNOT NOT BE
…I cannot have been:I must always have been as I am, since the past cannot have been different.
…I cannot have moved: I must always have been where I am, since motion, being change, is impossible.
…I cannot be unlike other things: Difference is impossible, so nothing can be unlike anything else.
…All that is, is one unchanging: what exists is one, and indivisible, like a perfect sphere.
✔ NEED TO KNOW
. Parmenides is sometimes called the “father” of ontology (the study of the nature of being, existence, and reality).
. The idea of two worlds – one of illusion and one of reality and truth – had a significant influence on Plato.
. The view that existence is a singular, unchanging entity is known as Parmenidean monism.
Zeno’s paradoxes
As a student of Parmenides, Zeno of Elea believed that all forms of change are illusory. To prove it, he devised a series of arguments that apparently demonstrate the impossibility of motion.
An unchanging reality
Like his mentor Parmenides, Zeno of Elea (c.490–430 BCE) was a pioneer of the use of logical arguments to justify ideas, even when these flew in the face of how things appear to us. The Parmenidean notion of an unchanging, eternal reality, for example, contradicts the evidence of our senses, but Zeno set out to show that the changes that seem to occur in the world are logically impossible, and nothing but an illusion. He did this by presenting a number of paradoxes – logical arguments that lead to apparently absurd conclusions.
The most famous of Zeno’s paradoxes are those that concern motion, which he regarded as a specific kind of change – that of an object’s position from one place to another. In the dichotomy paradox, he shows how a simple walk covering a finite distance can become an impossibly infinite task, involving the completion of countless stages. In the paradox of Achilles and the tortoise, he gives a step-by-step account of a race in which a fast runner can never catch up with a slower one, thereby ridiculing conventional ideas of speed and motion.
A third paradox concerns the flight of an arrow, and cleverly demonstrates that it is never actually moving. If we accept that an instant is a moment in time with no duration, then, at any given instant, Zeno argues, the flying arrow is in its present location and nowhere else. It occupies a static position in the air and is motionless. Time, he says, progresses through an infinite number of instants: if the arow is motionless at every instant, it is never moving. Motion is therefore impossible, so our experience of motion must be an illusion.
Zeno’s logic is apparently impeccable, and it is difficult to find any flaw in his arguments. Modern mathematical techniques, such as the calculus, have been used to resolve his paradoxes, but not to everyone’s satisfaction. The philosopher Bertrand Russell considered the paradoxes “immeasurably subtle and profound”, and Zeno a mathematical genius.
🔎 THE DICHOTEMY
In order to walk a certain distance, a person must first walk half of that distance. But before reaching that halfway point, they must get a quarter of the way, and before that an eighth, and so on without end. Walking any distance at all will therefore entail an infinite number of shorter stages, involving an infinite number of tasks, which will take an infinite amount of time to complete. The same is true for anything that apparently moves, proving that movement is in fact impossible.
Achilles and the tortoise
Probably Zeno’s best-known paradox tells of the race between the athletic warrior Achilles and a tortoise. To make the race fair, Achilles gives the tortoise a head start. Common sense suggests that Achilles will at some point overtake the tortoise, but Zeno succeeds in reasonably arguing that Achilles can do no more than narrow the gap between them.
[1] A Head Start – At the beginning of the race, the tortoise starts from a position some distance ahead of Achilles. As the tortoise slowly moves off from its starting point, Achilles rushes to catch up with it.
[2] Narrowing the Gap – By the time Achilles has reached where the tortoise began, the tortoise has moved on, so Achilles still has some distance to make up to draw level with it. The tortoise thus continues the next stage of the race with a head start, albeit a shorter one than before.
[3] Stuck in Second Place – When Achilles gets to the point that the tortoise had previously reached, the tortoise has again advanced to a position beyond it. At every stage in the race, Achilles can only reach the point where the tortoise has been, by which time the tortoise has moved further on.
“These writings of mine were meant to protect the arguments of Parmenides against those who make fun of him.” – Zeno of Elea (5th century BCE)
✔ NEED TO KNOW
. A paradox uses apparently sound logic to reach a conclusion that common sense suggests is ridiculous or contradictory.
. A fallacy is an error of reasoning, such as an invalid logical argument. Paradoxes are fallacies in which the flaws are difficult to identify.
. Zeno’s paradoxes are examples of reductio ad absurdum reasoning, which show the weaknesses of opposing arguments.
Elements and forces
In contrast to Parmenides’s static view of the cosmos, Empedocles proposed a theory of a dynamic system composed of four elements driven by the forces of attraction and separation.
Cosmic building blocks
Although he accepted Parmenides’s assertion that nothing comes from nothing, and that nothing can be destroyed, Empedocles (c.490–c.430 BCE) was uncomfortable with the idea of a singular and unchanging world. The world as he saw it is marked by plurality and change. To reconcile the two ideas, he proposed a theory based on the four elements (or “roots”, as he called them) that were identified by earlier philosophers: earth, water, air, and fire. These, he argued, are each immutable and eternal, satisfying the notion that nothing can be created or destroyed. Empedocles described these elements as the “building blocks” of the cosmos, from which all matter is formed. The various material substances are made from combinations of these elements in different proportions. But, unlike the elements, the substances formed from them are not unchangeable.
In this way, Empedocles explains that change in the world is not an illusion: the elements can separate as substances disintegrate and recombine in different proportions to form new substances. He believed that there is a constant process of change, and that the cosmos is a dynamic system characterised by the continual separation and combination of the four elements. To account for the behaviour of the elements, Empedocles took an idea from Heraclitus: the action of opposing forces. He argues that the cosmic forces of attraction and separation that underlie the formation of matter and even living things govern the ways in which the elements combine and disintegrate. The continual change inherent in the cosmos therefore results from the fluctuation in the balance or dominance of these opposing forces over time.
Love and Strife
Empedocles suggests that the changing nature of the cosmos is driven by two opposing cosmic forces: Love and Strife. Love is the creative force of attraction, which causes the elements to combine in various forms. Strife is the destructive force of repulsion, which separates the elements from one another, and therefore lies behind the decay of matter. The elements themselves are neither created nor destroyed, but constantly rearranged.
Love: The force of attraction, Love brings together the elements in various proportions and combinations to create the different material objects in the universe. The element of fire is what gives certain things life.
Strife: Material things are not permanent, but undergo a process of decay in which Strife, the force of repulsion, separates the elements. These elements can then reform in different combinations to make other things.
Cosmic cycle
The forces of Love and Strife are locked in a battle for dominance, creating an eternal cosmic cycle. When Love completely overcomes Strife, the elements cannot be separated from one another to form the various substances of the cosmos. In conflict with Strife, the elements separate, and matter and life can be created. However, when Strife prevails, all that was created dissolves into separate elements, until the influence of Love brings them together again.
Love dominates – The elements become too close, and life is impossible.
Strife increases – The elements are separated by Strife and life is born again.
Strife dominates – The elements are separated, and life is destroyed.
Love increases – The elements are brought together, and life is created.
🔎 The Origin of Species
In Empedocles’s version of the birth of the cosmos, he describes a rudimentary form of natural selection. The species originated as separate organs, which were brought together by the force of Love in various combinations, forming all kinds of strange creatures. However, those assembled wrongly were unable to breed, and only the “correct” species survived.
Immortal seeds
In his novel theory of the cosmos, Anaxagoras suggested that, as it derives from a single original substance, everything in the physical universe contains a portion of everything else.
Everything in everything
Like most philosophers of his time, Anaxagoras (c.510–c.428 BCE) accepted Parmenides’s arguments for the eternal nature of the universe but argued that there could also be change and diversity. According to Anaxagoras, the cosmos originates from a “mass” or unity consisting of inextricably linked particles, which are eternal and indestructible. These are the “seeds” of all physical matter, but in this primordial state they are indistinguishable from one another and have not yet assumed distinct forms.
The “mass” from which the cosmos began was at some point prompted to start spinning. This motion acted like a centrifuge, separating the particles, and arranging them into different substances. Each separate substance, like the unity it derives from, is a mixture of these infinitely small primary particles. While one particular type of seed might predominate to give the substance its distinct characteristics, every physical thing also contains seeds of every different type of matter. And so, everything contains a portion of everything else.
🔎 INFINITELY DIVISIBLE
According to Anaxagoras, each and every thing is characterised by the proportion of the substances that it contains. When divided in two, the proportion of substances remains the same in each half; the halves themselves can also be divided repeatedly, and each piece will still have the same consistency.
Substance stays the same
If the separate pieces of something are substantially the same, then, regardless of their size, they remain the same substance, even when divided into infinitesimally small pieces.
The cosmic mind
According to Anaxagoras, the primordial, unified mass of all substances was set into motion by nous, the cosmic mind, the fundamental force, and governing principle of the universe. As well as initiating the birth of the cosmos, nous determines the way that the “seeds” of physical substances are arranged to form distinct entities.
“The seed of everything is in everything else.” – Anaxagoras (5th century BCE)
Controlling force – The nous, or mind, both initiates the revolution at the origin of the cosmos and shapes the way things grow.
Varied materials form – From the mass of minute particles, the spiralling motion separates material substances from the air and ether and spins out solid and liquid elements (such as inanimate objects and plants, and humans).
Animals
The nature of food – Anaxagoras noted that animals often feed on substances that bear no resemblance to the animals themselves. The leaves that a goat eats, for example, bear no resemblance to the goat.
From foliage to fur – A goat eats nothing but leaves, which contain no visible traces of muscle, bone, or fur. However, the goat’s muscles, bones, and fur are constantly replenished by the leaves.
Portions of substances – For Anaxagoras, the leaves that the goat eats contain muscle, bone, and fur, albeit in minute quantities. The goat stays healthy if it regularly eats these minute quantities of muscle, bone, and fur.
✔ NEED TO KNOW
. The Greek word nous in Anaxagoras’s writings is often translated as “mind”, but it also means “reason” or “thought”.
. Anaxagoras is credited with bringing philosophy to Athens in around 460 BCE, and inspiring Socrates, Plato, and Aristotle.
. In later life, Anaxagoras left Athens for his own safety. According to some accounts, his unorthodox views led to him being charged with impiety.
Atomic Theory
In the 5th century BCE, the philosopher Leucippus and his pupil Democritus proposed the revolutionary notion that everything is composed of indestructible particles moving in empty space.
Atoms and empty space
Like many other philosophers, the Atomists, as they were later known, attempted to explain the reality of motion and change. Parmenides had said that these are mere illusions, since motion requires the existence of a void, which he deemed a logical impossibility.
Atomists turned this argument on its head, however, suggesting that since motion is patently possible, the void must exist, and matter must be free to move within it. Since the movement of matter takes place at a microscopic level, it is not visible. Matter is formed of minute particles that Leucippus called “atoms”, which exist in empty space, and the changes that can be observed in the cosmos are due to the motion of these atoms in the void. Each atom is an eternal and unchanging entity, both indestructible and indivisible, but capable of joining with others to form different substances and objects.
Where Parmenides posited eternal, immutable unity, the Atomists proposed an infinite diversity of eternal particles that gives rise to an ever-changing cosmos.
Building blocks
According to the Atomists, the atom is the basic unit of every material substance. These building blocks of matter are constantly in motion in the void, and react with each other, being either mutually repelled or attracted. There are countless kinds of atom, which join together in different combinations to form the huge variety of substances. They then separate as those substances decay. The atoms themselves are immortal and remain intact. They continue their movement through the void, continually and ceaselessly combining, separating, and reforming.
Indivisible atoms
An object such as a tree can be divided into its constituent parts, and the parts cut into pieces. But these parts are not infinitely divisible – at a fundamental level, the atoms themselves are indestructible.
✔ NEED TO KNOW
. The void described by the Atomists is more than empty space – it is an absolute absence of matter, akin to a vacuum.
. The word “atom” comes from the Greek atomon, meaning “uncuttable” or “indivisible”.
🔎 KINDS OF ATOM
Democritus suggested that atoms come in a range of sizes and shapes, their properties determining the characteristics of different substances. He proposed that the atoms of liquids are smooth and can move freely past one another, while solids have more rigid atoms that move less and can connect with other atoms.
Air – Air atoms are light and wispy and move freely and independently.
Water – The smooth, round atoms of water give it its flowing, liquid character.
Iron – Atoms of iron have hooks that interlock to give the metal its solidity.
Salt – The taste of salt is caused by its jagged atoms acting on the tongue.
“Nothing exists except atoms and empty space; everything else is opinion.” – Democritus (5th century BCE)
VISUALISATION AND SENSATION
Object – All objects emanate “image particles” of themselves, which enable them to be perceived.
Image – These image particles, which Democritus called “idols”, travel through the air in all directions.
Sensation – An image makes an impression on the atoms of the sense organs in the body, creating a sensation.
Psyche – The psyche (soul) is made of “fire atoms”, which interpret the sensations received by the senses.
Examining ideas
Socrates was a familiar sight in the marketplace in Athens, where he would engage citizens and students in philosophical discussion, challenging their preconceived ideas in his pursuit of knowledge.
The dialectic
Socrates (469–399 BCE) left no written record of his ideas, and famously declared that all he knew for certain was that he knew nothing. Much of what is known about his thinking comes from his student Plato, who wrote a series of texts featuring Socrates as the protagonist, extracting and analysing ideas in a masterful way. It is his method of eliciting and examining an argument – elenchus in Greek, meaning cross-examination or inquiry – that earned him his place as one of the foremost Athenian philosophers.
According to Plato, Socrates described himself as a sort of intellectual “midwife”, helping to give birth to ideas. His method was simple, using a process of question and answer known as “the dialectic” – a dialogue between opposing views – that digs gradually deeper into the topic of discussion. The opening question is often a deceptively simple one, in which Socrates typically asks for a definition of a concept, such as “What is courage?” or “What is virtue?”. He then examines the answer, pointing out any inconsistencies or contradictions in it, asking for an elaboration of the answer to account for them. This method gradually highlights any assumptions and preconceptions, uncovering the deeper meaning of the topic, and taking it back to first principles.
Socrates then sifts out opinions and arguments that can be refuted, leaving only that which he knows to be true. From this, he uses the dialectic to construct a better-informed argument. Although such discussions often end without reaching a conclusive answer, Socrates’ key contributions were to provide a new way of examining existence, and extending philosophy to include morality and justice, not just the physical world.
“An unexamined life is not worth living.” – Socrates (5th century BCE)
✔ SOCRATES’ LEGACY
As well as pioneering the dialectic, Socrates distinguished between knowledge that is gained through reflection and knowledge that is gained via the senses. Although he placed little emphasis on the distinction, it was one that his successors developed into the rival schools of rationalism and empiricism.
An early form of rationalism was held by Socrates’ most famous student, Plato, who believed that our experience of the world is deceptive, and that true knowledge can be gained through rational reflection alone. Plato’s own most brilliant student, Aristotle, argued the opposite idea – that knowledge is arrived at by observation only. The latter idea became the central tenant of empiricism. In modern times, rationalism was revived by René Descartes, and empiricism by John Locke.
Socratic irony
According to legend, Socrates began a campaign of inquiry after he learned that the oracle at Delphi had pronounced him the wisest man in the world. Socrates set out to prove the oracle wrong but discovered that most people in fact knew less than he did. Socrates feigned ignorance of a subject in order to start his discussions, but as he pointed out the inconsistencies in the replies, it became apparent that he knew more than he admitted. Claiming ignorance to elicit a response in this way has since become known as “Socratic irony”.
An example of the dialectic in use:
A asks: [1] What is courage?
B replies: [2] The capacity to endure?
A asks: [3] And is courage an admirable quality?
B replies: [4] Yes, very admirable.
A asks: [5] What about foolish endurance, like obstinacy? Would that be admirable?
B replies: [6] No, it wouldn’t.
A says: [7] So endurance with foolishness is not courage because it is not admirable. So courage is not just the capacity to endure. It must be coupled with good sense.
Platonic realms
At the heart of Plato’s philosophy is the notion that the world we live in is deceptive, and that our senses cannot be trusted. Indeed, for Plato, our world is merely a shadow cast by a higher realm of the Forms.
A world of Forms
Plato, like many philosophers before and since, was an accomplished mathematician, and was fascinated by geometry. He observed that there are many instances of things that are, for example, circular in the world about us, and that we recognise them as instances of a circle. We can do this, he argued, because we have an idea in our minds of what a circle is – what he called the “Idea” or “Form” of a circle – and unlike the particular instances of circular things, this Form is an ideal circle, with no imperfections. Indeed, everything we experience – from horses to acts of justice – are particular things that we recognise by comparing them with their relative Forms in our minds. Moreover, Plato claimed that since we cannot perceive these Forms, they must exist in a realm beyond our senses – one that we recognise with our psyche, or intellect. This process of recognition is largely instinctual, but Plato argued that philosophers are needed to comprehend certain Forms. Indeed, for Plato, philosophers ought to be kings: they should organise society and advise on ethical matters.
Forms and particulars
According to Plato, only imperfect, particular things exist in our world. The ideal circle, for example, exists only in the world of the Forms. The Forms are like blueprints from which particular things are made.
Material objects – There are many kinds of horse, but all are recognisably horses because they conform to the ideal Form of a horse. All our ideas of “horsiness” are derived from the ideal Form.
Abstract concepts – There are also Forms of abstract concepts, such as truth, beauty, and virtue. Instances of justice in the earthly realm, for example, are reflections of the ideal Form of the concept of justice.
“If particulars are to have meaning, there must be universals.” – Plato (4th century BCE)
🔎 DUALISM
In Plato’s dualistic universe, the two worlds he describes are perceived in different ways. The earthly realm is experienced by our bodily senses; the ideal realm is understood by the psyche – our mind or intellect.
Plato’s ‘Allegory of The Cave‘
In the Republic, Plato presented an allegory to show how our knowledge of reality is restricted by the deceptive information provided by our senses.
A world of shadows
Plato asks us to imagine a cave in which some prisoners are held captive. They are shackled to face the back wall of the cave and are unable to turn their heads. Their field of view is restricted to the wall in front of them, across which they can see images moving.
The captives are unaware that behind them, hidden by a low wall, another group of people are parading a variety of objects in front of a fire. It is the shadows of these objects that the prisoners can see in front of them. Because all the prisoners can see are the shadows, this is the only reality of which they are aware. They know nothing of the objects casting the shadows and would not believe it if they were told about them. They are literally being kept in the dark about the true nature of the world that they inhabit. The point that Plato is making is that our own perception of the world is similarly restricted, and that the things we believe to be real are merely “shadows” of the things that exist in the ideal realm of the Forms.
Escaping the cave
Suppose that a prisoner in the cave is freed from her chains. As she looks behind her, she would be dazzled by the light of the fire but would slowly make out the objects whose shadows she had mistaken for reality. She might then be persuaded to leave the cave, and, after initially being blinded by the sunlight, she would see that there is more to reality than the world inside the cave. However, if she returned to the cave, she would find it difficult to convince the other captives of her discovery that their reality is an illusion.
[1] Restricted Experience – All that the prisoners can see, and have ever seen, is the back wall of the cave. What they view there is the limit of their experience of the world.
[2] Illusory Images – The prisoners see images of things on the wall, which, as they have experience of nothing else, they assume to be reality. What they cannot know, because they cannot turn around to see it, is that these are only the shadows cast by other objects.
[3] Realising the Deception – A freed prisoner can see behind her and realise that she has been deceived: there is more to the world than the images projected onto the wall.
[4] Seeing the Light – At first, she is dazzled by the light of the fire, but then observes the objects and how they are responsible for casting the shadows.
[5] Emerging from the Dark – If the prisoner is led out of the cave, once her eyes are accustomed to the sunlight, she sees things that she never knew existed.
[6] A Superior World – The world she discovers is reality. For Plato, the philosopher’s role is to encourage people to leave the cave – that is, to comprehend the limits of their experience.
“Earthly knowledge is but a shadow.” – Plato (4th century BCE)
🔎 INNATE KNOWLEDGE
Plato believed that our knowledge of the Forms is something we are born with, not something we acquire through experience. Rather, we use our reason to access the Forms, in whose realm we lived before we were born. For Plato, philosophers are like midwives: their role is to bring to light what we innately already know.
One world only
Plato’s most brilliant student, Aristotle, did not agree with his mentor’s theory of Forms. Instead, he proposed that we learn about the world through experience alone.
Empiricism
Aristotle could not accept the idea of a separate world of ideal Forms. Plato had argued that the Forms – the qualities of being circular, good, or just, for instance – exist in a separate realm. Aristotle believed that there is only one cosmos, which we learn about through our experience of it. Although he accepted that “universal” qualities (such as redness) exist, he did not believe that they do so in a separate dimension. Rather, he said, they exist in each particular instance in this world.
For example, the idea of a “circle” is general: we have in our minds an idea of what constitutes a perfect circle. He explains that this is not because we have innate knowledge of the perfect (Form of a) circle, but because we experience circular things, and then generalise about them, having seen what they have in common. For Aristotle, we gather information about the world through our senses and make sense of it by using our intellect or reason. In this way we build up ideas, apply labels to them, and make distinctions. As a philosophical stance this is known as “empiricism”, as opposed to Plato’s “rationalism”.
Using experience
Aristotle argued that we learn general concepts by experiencing particular instances: our idea of a cat is built from our experiences of many different cats. We use reason to grasp the general idea “Cat”.
[1] Unscribed Tablet: According to Aristotle, we have no innate knowledge. When we are born, our minds are like “unscribed tablets” waiting to be written on. We build up our knowledge by learning from our experiences.
[2] Objects: The knowledge we obtain about the world comes from our senses. For example, we gather information about the instances of various objects we see with our eyes, which is then transmitted to our minds.
[3] Ideas: By using this information from our senses, we can form ideas in our minds. For instance, from our daily experience of the Sun we build an idea of the Form of the Sun and its defining characteristics.
[4] Names: We then attach labels to these ideas, giving names to the forms in our minds. In this way, we learn to recognise things by their characteristics, and to distinguish between different things.
✔ ESSENTIAL AND ACCIDENTAL PROPERTIES
Aristotle argued that all things have two kinds of properties. An essential property is what makes a thing what it is. Its other properties are “accidental” properties.
. An apple’s accidental properties include its colour, shape, and weight. It is an apple whether it is green or red, round, or oval, large or small.
. The apple’s essential property is the substance that it is made from.
. The essential property of a ball, however, is its shape; the substance it is made of is an accidental property.
✔ NEED TO KNOW
. Epistemology is the branch of philosophy concerned with knowledge and the way we acquire it.
. Inductive reasoning is the logical process of making a general rule from a number of particular instances.
. Empirical knowledge is knowledge that is acquired by observation or experience rather than through reasoning.
Form is function
Aristotle argued that to understand a thing is to know four things about it: what it is made of; how it came into being; its design; and what function it performs.
Matter and form
In their efforts to understand the nature of things, the pre-Socratic philosophers focused on the “stuff” that things are made of – the matter of the cosmos.
Aristotle, however, noted that there is more to a thing than its physical make-up. For him, to know a thing is not only to know what it is made of, but also what processes brought it into being, what shape (or design) it takes, and what purpose it serves. Aristotle called these the “four causes” and argued that we only understand a thing when we know its four causes. This radically departed from the teachings of the Atomists, for example, who rejected the notion that there are purposes in nature, favouring what Aristotle called “efficient causes” only.
For Aristotle, clay can be used to make bricks, crockery, drainpipes, and even statues. All of these share the same matter, but each has its own form. The form of a statue, for instance, is different from that of a bowl because the function of a bowl (to contain food) is different from that of a statue (to honour a person). However, even unformed clay has a function, and that is to become those various forms. For Aristotle, matter without form cannot exist. What he calls “prime” matter is pure potential: it is yet to unfold into the various forms it can take.
The four causes
Aristotle explained the nature of a thing in terms of its physical make-up, its design, the circumstances that brought it into being, and its purpose or function. Together these four causes tell us all we need to know about a thing and go far beyond the Atomists’ claim that a cause is simply a physical event that brings a thing into being. The Atomists’ view came back into vogue with Galileo, who saw “efficient causes” as the only causes relevant to modern science.
[1] Material Cause – The material cause of a thing is the matter from which it is made. In the case of a sculpture, the material cause is a slab of stone.
[2] Formal Cause – The formal cause of a thing is its physical design. The formal cause of a sculpture is the blueprint prepared by its maker.
[3] Efficient Cause – The efficient cause of a thing is the physical process that brings it into being. The efficient cause of a sculpture is its sculptor.
[4] Final Cause – The final cause of a thing is the purpose for which it has come into being. A statue of Aristotle, for example, serves to honour the man it depicts.
✔ NEED TO KNOW
. Aristotle’s four causes are not causes in the modern sense, but explanations or reasons for things coming into being. For Aristotle, all things have a purpose, and are fully known by understanding their four causes.
. “Form” in Aristotle’s ontology refers to what makes a thing specifically what it is, its essence, and is different from Plato’s idea of a perfect Form on which a thing is modelled.
. Aristotle’s idea that a substance is a combination of matter and form is known as “hylomorphism”.
✔ THE SUBSTANCE OF THINGS
According to Aristotle, the substance of a thing – that which makes it what it is – is more than simply the material from which it is made. All sorts of things can be made from clay, and it is the form of the clay that makes it, for example, a bowl. The substance of a thing is therefore its matter and its form. Later philosophers argued that since the substance of a thing underlies its physical nature, transubstantiation is also possible.
Substance = Matter + Form
Substance: The substance of a bowl is what makes it what it is – a vessel for containing food.
Matter: The matter of the bowl is the material from which it is made – clay.
Form: The form of the bowl is its shape, which enables it to contain food.
“The aim of art is to represent not the outward appearance of things, but their inward significance.” – Aristotle, Poetics (4th century BCE)
An Earth-centred cosmos
Aristotle’s concept of a cosmos with the Earth at its centre, surrounded by heavenly spheres, was the model for astronomy for almost 1,900 years.
The Earth and the heavens
Aristotle believed that the Earth and the heavens are distinct regions, with a boundary between them marked by the orbit of the Moon. In the terrestrial, or sublunary, region, the matter from which everything is made consists of the four elements: earth, water, air, and fire. According to Aristotle these elements tend to move up or down, seeking their natural place of rest. The earth element tends to move downwards, towards the centre of the Earth; water is inclined to settle on the Earth’s surface; above that floats the air; and finally, there is fire, which rises to the top.
The heavenly spheres
In line with his contemporaries, Aristotle believed that the circle was the perfect geometric figure. For this reason, he naturally thought that the heavenly bodies beyond the Moon moved in circular orbits. The model of a perfect, eternal, geocentric cosmos was accepted for almost all subsequent astronomical thought until Nicolaus Copernicus, championed the idea of a heliocentric universe in 1543.
The geocentric universe
Outside the orbit of the Moon lies the celestial region in which the Sun, the planets, and the stars move in orbits at various distances from the Earth. Unlike the sublunary region, the celestial region is made from an incorruptible substance, which Aristotle calls the “quintessence”, or fifth element. According to Aristotle, the natural movement of the earthly elements is up or down, towards or away from the centre of the Earth. By contrast, the natural movement of things in the celestial region is circular. What’s more, earthly elements tend towards a position of rest, while celestial movement is unceasing. Thus, Aristotle reasoned that the stationery Earth, although imperfect, is at the centre of the cosmos.
Beyond the Moon’s orbit, Aristotle identified 55 concentric spheres to which the celestial objects are attached. As they radiate away from the Earth, the outer spheres draw closer towards perfection, stretching into spiritual realms that have no material existence. The universe, for Aristotle, is a perfect form, and cannot have come into being at any one time: it is eternal, unchanging.
KINDS OF SOUL
According to Aristotle, everything consists of both matter and form. The matter of living things is made up of the elements, but their form is the psyche, or soul, which gives them life. Different kinds of soul determine the natures of plants, animals, and humans.
. Vegetative: Plants have only a vegetative soul with the ability to grow and reproduce.
. Sensitive: Animals have sensitive souls. They can move and experience sensations.
. Rational: Unique to living beings, humans have rational souls, which can think and reason.
🔎 COMPOUND BEINGS
For Aristotle, everything in the terrestrial region is a combination of the four elements in varying proportions, giving beings their distinctive characteristics. The natural tendency of the elements to seek an appropriate level exerts an upward or downward force: rooting plants to the Earth or giving animals their mobility.
For example, a tree may have more earth, less water, more air, and less fire, than a cat.
Purposes in nature
According to Aristotle, everything that exists has a final cause, or purpose – what in Greek is called a telos. In other words, everything in nature exists to fulfil a goal.
Teleology
Explaining things in terms of their purposes was not unusual among classical Greek philosophers, but today it stands at odds with our modern, scientific understanding of the world. To our modern eyes it is quite normal to describe a man-made object, such as a tool, in terms of its function or purpose. A hammer, for example, exists for the purpose of pounding in nails. But this is an extrinsic purpose, one that is imposed upon it from the outside. What Aristotle proposed was that everything, including everything in the natural world, has an intrinsic purpose: that is, each thing exists in order to achieve its own ends – its internal purpose. For example, a seed’s purpose is to germinate and become a plant, and trees exist in order to produce fruit.
For Aristotle, it is not only living things that exist for a purpose. Rain falls in order to moisten the ground and enable plants to grow. It is the rain’s telos to water the earth, and the plants’ telos to grow. Their purpose or goal is the reason they have come into being.
More in line with our modern thinking is the Atomists’ assertion that natural things do not have an intrinsic purpose or “final cause”: instead, their existence is the cause of other things. Rain does not fall in order to water the plants; rather, the plants use the moisture that happens to have been provided by the rainfall.
Causation
Aristotle’s theory of causation is based on his theory that everything has four causes. What we usually think of as a cause – that which makes a thing happen – is what Aristotle calls an “efficient cause”. For example, a person who pushes a rock downhill is the efficient cause of the rock’s movement. The purpose, or “final cause”, of its movement – why it goes downwards instead of up or sideways – is that it is seeking the centre of the Earth. The final cause of the action of pushing the rock is to see how far it will roll. The rock’s movement is also determined by formal and material causes.
[1] Efficient Cause: The efficient cause in this particular instance is the woman who pushes the rock. The rock moves because of her actions.
[2] Material Cause: The material cause is the rock’s physical composition. The rock is made of earth, and so, because earthy things seek the centre of the Earth, it moves downwards.
[3] Formal Cause: The formal cause – the shape of the rock’s trajectory – is determined by the landscape. The rock’s rolling and bouncing are caused by the slopes and bumps of the hill.
[4] Final Cause: The rock comes to a rest when it reaches the closest it can get to the centre of the Earth – the bottom of the hill.
✔ THE UNFOLDING WORLD
For Aristotle, the essential property of a seed is its ability to grow. That is also its intrinsic purpose: it exists to become a plant, which, in turn, exists in order to produce seeds. Living things are therefore characterised by their tendency to move or change, and to reproduce. And, since all terrestrial things are imperfect and impermanent, beings not only grow, but also eventually perish and decay.
🔎 THE UNMOVED MOVER
Aristotle’s universe had no beginning, but Aristotle believed that something must have set the heavenly bodies in motion, since everything is caused by something else. However, this raises two questions: What caused that cause, and what moved the mover of the universe? Aristotle proposed the idea of a first cause, an “unmoved mover”, responsible for all the motions in the universe.
“It is […] necessary always to investigate the supreme cause of every thing.” – Aristotle, Physics (4th century BCE)
Fire – The element fire rises to take its position above the air. A volcano’s purpose, for instance, is to enable the fire to escape from the Earth.
Rain – Water in the air, in the form of clouds, has a downward tendency, and falls to settle on the Earth, moistening it.
Tree – The nature of trees, determined by their vegetative souls, is to grow in order to produce fruit to reproduce.
Scholastic philosophy
Medieval European culture was dominated by the Catholic Church, and the classical philosophy of Plato and Aristotle was only gradually assimilated into Christian teaching.
Catholic theology
The establishment of the Christian Church marked the end of the period of classical antiquity. Philosophy was regarded with some suspicion by early Christians, who considered its basis in reason, rather than faith, as incompatible with Christian doctrine. There were some, such as Augustine of Hippo (354–430 CE) and Boethius (c.477–524), who found ways to reconcile the idealist philosophy of Plato with their faith, but for several centuries the Church’s monopoly on learning prevented the spread of classical philosophy in Europe. This changed in the 12th century when medieval scholars rediscovered and translated the classical Greek texts. Many of these had been preserved by Islamic scholars, who had translated them into Arabic.
Although it was relatively simple to incorporate Plato’s idealist and sometimes mythical ideas, Aristotle’s texts seemed at first to be contrary to Catholic dogma. His systematic reasoning, however, inspired a new approach to teaching, which became known as scholasticism. Education spread from the monasteries to newly founded universities in cities across Europe, where Aristotelean logic and dialectical reasoning were taught as a method for examining theological arguments, and to provide rational justification for the various pillars of Christian faith.
Although the first translations of Greek philosophers originated in southern Europe, with its links to the Islamic world, scholasticism arose in the scholarly work of Christian philosophers, such as John Scotus Eriugena in Ireland in the 9th century. By the 12th century, the scholastic tradition was flourishing across Europe. Among its most influential philosophers were Anselm of Canterbury (1033/4–1109), Peter Abelard (1079–1142), Duns Scotus (c.1266–1308), William of Ockham (c.1287–1347), and, a major figure in medieval European philosophy, Thomas Aquinas (1225–74).
The schools that were established to provide scholastic education thrived for several centuries, and many still exist today. However, with the arrival of the Renaissance, scholasticism’s emphasis on theology was replaced by scientific and humanist ideas.
✔ CREATING ETERNITY
A major stumbling block for Christian philosophers trying to integrate Aristotle into Catholic doctrine was Aristotle’s assertion that the universe has no end and no beginning, contradicting the Bible description of God’s creation of the world. Thomas Aquinas, however, believed that since human reason and Christian doctrine are both gifts from God, they cannot be contradictory. Using his God-given reason, he argued that Aristotle was not mistaken in his concept of an eternal universe, but that God was indeed its creator: in the beginning, God created the universe, but could have also created a universe that is eternal.
The ontological argument
In attempting to reconcile faith and reason, a problem for scholastic philosophers was to provide a rational argument for the existence of God. Probably the first of the Christian philosophers to present such an argument was Anselm of Canterbury. His reasoning, known as the ontological argument, defines God as “that than which nothing greater can be thought”. From that premise he methodically shows that if God exists in our imagination, then an even greater God is possible: one that exists in reality. Thomas Aquinas later identified four other arguments for the existence of God, derived from Aristotle’s idea of an “unmoved mover” or first cause.
“For I do not seek to understand in order to believe, but I believe in order to understand.” – Anselm of Canterbury (11th century)
[1] God is the greatest thing we can think of
[2] God exists as an idea in the mind
[3] Things can exist only in our minds or they can exist in reality
[4] Things that exist in reality are always better than things that exist only in our minds
[5] If God exists only in our imaginations, he wouldn’t be the greatest thing conceivable, because God in reality would be better
[6] Therefore, God must exist in reality
Transubstantiation
Using the Aristotelean notions of substance, matter, and form, Thomas Aquinas argued that, in the Catholic Mass, bread and wine actually become the body and blood of Jesus.
Changing form
One of the most important philosophers of the scholastic tradition, Aquinas was largely responsible for incorporating Aristotelean ideas into Christian theology. The down-to-Earth philosophy of Aristotle appeared to be at odds with several tenets of Christian dogma – not least that God created the universe – but Aquinas saw that it was not only compatible with Catholic doctrine, but actually helped to explain it.
A particularly tricky problem was how to provide a rational, philosophical justification for belief in transubstantiation – the actual changing of bread and wine into the body and blood of Christ, which the Catholic Church claimed took place. To do this, Aquinas turned to Aristotle, whose ideas were only gradually gaining acceptance by Christian philosophers.
In true scholastic fashion, Aquinas rigorously applied rational argument to what seemed to be simply an article of faith. According to Aristotle, substance is a mixture of both matter and form. Transubstantiation is a transformation of one substance into another: specifically, from bread and wine into flesh and blood. And so, Aquinas reasoned that it is not the matter of the bread and wine, the physical materials they are made of, that undergo this change, but their form. He argued that the consecration of the bread and wine changes their function or purpose – as food and drink – into a sacred offering. And, therefore, by changing their essential properties, the substance (the combination of both matter and form) of the bread and wine is transformed into the flesh and blood of Christ.
“Reason in man is rather like God in the world.” – St Thomas Aquinas (13th century)
Substances
According to Catholic doctrine, the bread and wine consumed by the congregation in the Mass are transformed by the prayers said by the priest into the body and blood of Christ. However, in Aristotelian terms, it is not their matter that is altered, but their form – the function that they serve and their essential properties. Their physical, or “accidental” properties, remain the same.
Occam’s razor
William of Ockham was both a Franciscan friar and a scholastic theologian. His most famous idea, known as Occam’s razor, was that given two competing hypotheses, we should choose the simplest.
Shaving away irrelevance
In a nutshell, the principle of “Occam’s razor” states that one should “shave away” all unnecessary assumptions when constructing or assessing the validity of an argument. In Ockham’s own words: “plurality should not be posited unnecessarily”.
The premises of any argument have to be accepted as true, but the fewer assumptions that are made, the better. When there are alternative explanations for something, all things being equal, the one with the fewest variables is most likely to be correct. In practice, this principle has come to be adopted in the form of “the simplest solution tends to be the right one”. However, Ockham’s notion is rather more subtle: the more assumptions that are made, the less convincing the argument, so it is easier to decide between alternative hypotheses if irrelevant or fanciful assumptions are removed.
Heliocentrism
Early astronomers observed that Mars appeared not to follow a regular, circular orbit around the Earth, but in fact made periodic “detours”. They offered various complicated explanations for the regular, but eccentric, orbit of Mars; but a simpler explanation is that all the planets revolve around the Sun.
Q: Why does Mars appear to turn back on itself in the sky?
✗ [1] A passing entity disturbs it.
✗ [2] It regularly loses its way.
✔ [3] It’s an illusion. The Earth overtakes Mars as they both orbit the Sun.
“Entities should not be multiplied beyond necessity.” – William of Ockham (14th century)
The Scientific Revolution
Although the Renaissance was primarily an artistic and cultural movement, its emphasis on free thinking challenged the authority of religion and paved the way for an unprecedented age of scientific discovery.
Tradition undermined
The Scientific Revolution began with the publication in 1543 of Nicolaus Copernicus’s De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), which presented evidence contradicting the notion of a geocentric universe (see above: An Earth-centred cosmos). That same year, Andreas Vesalius published De humani corporis fabrica (On the Fabric of the Human Body), which overturned many orthodox ideas in anatomy and medicine. What followed was a profound change in the approach to enquiry into the natural world. Conventional wisdom, including the dogma of the Catholic Church, was no longer blindly accepted, but challenged. Even the work of Aristotle, who had initiated the idea of natural philosophy based on methodical observation, was subjected to scientific scrutiny.
At the forefront of this scientific revolution were philosophers such as Francis Bacon, whose Novum Organum (New Instrument) proposed a new method for the study of natural philosophy – systematically gathering evidence through observation, from which the laws of nature could be inferred. But there was also a new class of thinkers and scientists, including Nicolaus Copernicus, Johannes Kepler, and Galileo Galilei. Galileo challenged dogma more than most by proving that the Earth orbits the Sun and fell afoul of the Church for his efforts.
The discoveries made by these scientists, and the methods they used, laid the foundations for the work of Isaac Newton in the following century, and also influenced philosophers such as Descartes, Spinoza, and Leibniz, who helped to shape the ideas of the Age of Enlightenment.
ONE CAUSE ONLY
Central to Aristotle’s philosophy was the concept of the “four causes” (see above: Form is Function). The new scientific methods of the 16th and 17th centuries rejected these, especially the concept of a “final cause”, or purpose. Instead, it was proposed that there are only “efficient causes” in nature – i.e., physical casual triggers. Although this is closer to the modern idea of cause and effect, the idea had first been proposed by the Atomists some 2,000 years earlier (see above: Atomic Theory).
Laws of nature
The theories of Copernicus and his contemporaries heralded a new era of scientific discovery. Religious authority was undermined, but so too was the orthodox concept of the laws that governed the universe, which were based on Aristotelean cosmology and physics. In this new atmosphere of scientific enquiry, conventional assumptions were replaced with laws of nature derived from empirical evidence of observation and experiment.
“In science the authority of thousands of opinions is not worth as much as the reasoning of one individual.” – Galileo Galilei
✔ THE NEW METHOD
Induction – Bacon described a method of scientific enquiry using the process of induction, inferring a general rule from particular instances. For example, the rule that water boils at 100°C can be inferred because this is the case in every instance.
Experimentation – Often is not enough simply to observe in order to come to a scientific conclusion. The scientific method pioneered by Islamic philosophers involves conducting controlled experiments to get reproducible results.
Sunspots: The detailed study of sunspots made by Galileo and others showed that these are inherent features of the Sun. These observations contradicted the Aristotelean idea of the perfection of objects in the heavenly spheres.
Gravity: Although it may only have been a thought experiment, Galileo dropped two balls of different weights from the Tower of Pisa to show that they fell at the same speed. This refuted Aristotle’s assertion that heavy objects fall faster than lighter ones.
Elliptical orbits: Once it was proven that the Earth orbits the Sun, the orbits of the planets could then be explained. Kepler discovered that the orbit of Mars was not circular, but an ellipse, and concluded that all the planets had elliptical orbits.
Doubting the world
With probably the best-known statement in Western philosophy, René Descartes ushered in a new approach to philosophical enquiry that would come to be known as rationalism.
I am thinking, therefore I am
Inspired by the Scientific Revolution of the 16th and 17th centuries (see above: The Scientific Revolution), philosophers looked for a method for reliably acquiring and testing scientific knowledge. Francis Bacon, for example, advocated a method of observation, experiment, and inductive reasoning. Descartes, however, was uncomfortable with this approach. Instead, he proposed a reflective method, the aim of which was to find rational principles to serve as foundations for knowledge gained through observation and experiment. He argued that our senses our unreliable, and that we can doubt everything that they tell us. However, if we doubt everything, there must at least be something that doubts – an “I” that experiences doubt. As Descartes put it: “Cogito, ergo sum” – “I am thinking, therefore I exist”.
The primacy of reason
This was the necessary truth that Descartes was looking for, and it came not from his senses, but from his intellect. From this insight, he developed a theory of knowledge that dismissed sensory experience as unreliable, and instead proposed that knowledge is primarily acquired by deductive reasoning.
“This proposition, I am, I exist, is necessarily true.” – René Descartes, Discourse on the Method (1637)
The method of doubt
Descartes’ method of doubt is presented in his Discourse on the Method (1637). His goal was to show both that certainty can be gained through deductive logic alone and that science and reason are compatible with the Christian faith. His argument laid the foundations of modern rationalism – the belief that knowledge comes primarily from reason rather than experience. This view became popular in Europe and stood in contrast to the British tradition of empiricism, as exemplified by John Locke.
[1] I cannot trust my senses – My senses can be deceived by things such as optical illusions like a straw bending in water (called refraction in science). Therefore, they are not reliable sources of information about the world.
[2] I may be dreaming – When I am dreaming, what I experience often seems to be real. Therefore, I cannot be sure that what I am experiencing now is not a dream.
[3] A demon may be tricking me – Although unlikely, it is even possible that an evil demon is playing tricks on me, making me believe things that are not real. Even my body may be an illusion.
[4] Cogito, ergo sum – If my body could be an illusion, there must be something other than my body that suspects this. Therefore, that thinking thing – which is me – must necessarily exist.
[5] God accounts for me – I necessarily exist, but I have not created myself, therefore there must be something greater than me that created me: God.
🔎 THE DISEMBODIED SELF
Descartes dismissed sensory perception as unreliable: the only thing that he could be sure of was his own existence as a thinking thing. The essential self is therefore the mind and is distinct from and independent of the physical body.
Mind and body
By drawing a distinction between the mind and body, and prioritising reason over observation, René Descartes laid the foundations for modern rationalist philosophy.
Cartesian dualism
Descartes regarded the ability to reason as the defining feature of human beings. He believed that we have this ability because we possess a mind, or soul, which he saw as distinct from the physical body. He distinguished the mind from the body while engaged in his “method of doubt”, which was his unique method of philosophical enquiry [see above: Doubting The World].
This method of doubt was a sceptical approach, and led Descartes to conclude that our senses are far from reliable. Truth, he decided, can only be arrived at through reason. His claim “Cogito ergo sum” (“I am thinking, therefore I exist”) expressed his realisation that the only thing he could be certain of was that he existed – that in order to think at all, he must exist. In addition, he realised that he was a thing that thinks – but not a physical thing, for he could doubt that his physical body was real. He concluded that there were two distinct parts of his existence – an unthinking physical body, and a thinking, non-physical mind.
This led Descartes to conclude that there are two different types of substance – one material and one immaterial – in the universe. This view became known as Cartesian dualism. It raised the question of how the two substances interact, which is still debated today. Descartes claimed that mind and body “commingle” in the pineal gland of the brain, but he failed to show how they do so, and for many, including Thomas Hobbes, this failure undermined Descartes’ theory.
In Descartes’ day, sophisticated machines were being constructed – some even behaved like living things – and scientists believed that the world was mechanical, too: animals, the weather, and the stars were seen as machines whose movements could in principle be predicted. Descartes shared this view about everything except human beings: he claimed that we alone have the God-given attribute of reason.
🔎 THE PINEAL GLAND
Descartes believed that the mind and body are two distinct entities, but conceded that there had to be some interaction between the two. In particular, he thought that the mind exercises control over the body. Indeed, our rational freedom – our ability to choose how to act – is a definingly human characteristic. However, there must then be a place where our minds interact with our bodies. Descartes suggested this is the pineal gland, which is located in the centre of the brain. He described it as “the principal seat of the soul, and the place in which all our thoughts are formed”.
Two worlds
Descartes accepted the prevailing scientific view that all material things are mechanical. However, he believed that the immaterial mind is a uniquely human, God-given attribute, and that its ability to reason enables us to gain knowledge of immaterial things such as God, mathematics, and various physical laws.
🔎 MIND AND SOUL
Mind – For Descartes, the mind is the immaterial part of our being – the thinking thing that has the ability to have ideas. It is not located in space, and can doubt everything that it perceives – even the reality of the eyes through which it sees.
Soul – According to Descartes, because the mind is immaterial, it is not subject to physical decay. It is therefore eternal and synonymous with the immortal soul or spirit. For Descartes, dualism was compatible with religious faith.
The immaterial world
For Descartes, the immaterial world is the world of ideas, thoughts, and the spirit. It is composed of an immaterial substance that cannot be experienced by the senses, but which we have access to through reason, or rational thought.
The material world
The physical world is composed of a material substance, which we experience with our senses. It is unthinking and mechanistic, and is governed by the laws of physics. Our physical bodies consist of a material substance, and without our immaterial minds we would simply be unthinking machines.
✔ NEED TO KNOW
. An influential mathematician as well as philosopher, Descartes invented the system of Cartesian coordinates and established the field of analytical geometry.
. According to Descartes, the mind, or soul, is unique to human beings. Other animals are purely physical beings and behave in predetermined ways.
. Descartes’ mind/body dualism is regarded as the foundation of modern Western philosophy. However, in the 19th and 20th centuries, materialism increasingly became the norm.
The body as a machine
René Descartes’ mind/body dualism sparked a debate that continued through the 17th and 18th centuries. Foremost among those who rejected Descartes’ theory was a British philosopher, Thomas Hobbes.
Physicalism
Thomas Hobbes (1588–1679) was a contemporary of Descartes’ and corresponded with him about mathematics. However, he differed from Descartes on the subject of dualism. He did not accept Descartes’ idea of an immaterial substance, which he considered a contradiction in terms: a substance by its nature must be material. Following that belief, he argued that if there are no immaterial substances then everything must be material – a view that has since become known as physicalism. Hobbes took a particular interest in the natural sciences and was influenced by the ideas of Galileo. Like many other thinkers of the time, he thought that the universe behaves like a machine, and so is subject to physical laws. The movements of the planets and other heavenly bodies are explained by these laws, which apply to all physical objects. If, as Hobbes believed, humans are purely physical, then we too follow the same laws, and are effectively biological machines. Even our minds, Hobbes argued, are physical: our thoughts and intentions are not evidence of some immaterial substance, but the result of physical processes in our brains.
Hobbe’s concept of a purely physical universe was a radical departure from conventional thinking at the time, especially since it denied the existence of an immaterial God. However, it provided a counterargument to rationalism (see above: Doubting The World) and paved the way for a distinctively British empiricist approach to philosophy.
🔎 MIND-BRAIN IDENTITY
Hobbes did not distinguish between the substances of mind and body: he argued that there is only physical substance, so the mind and the brain are one and the same thing. This means that the thoughts and feelings that we experience are physical events in the brain, which are prompted by information provided by our senses. These thoughts and feelings are not made of some form of immaterial substance but can be understood in terms of physical processes. This idea was reformulated in the 20th century as the mid-brain identity theory.
Cogs in the machine
For Hobbes, physical laws govern the universe, which is made of many component parts, each of which has its own function, and is governed by physical laws. The natural world forms one such part of the universe, and within it plants, animals, and humans each play their part. Humans have organised themselves into societies, and these in turn are governed by laws. Biologically, each human being is a complex machine, composed of numerous functioning parts, all of which are controlled by physical processes within the brain. The brain itself is controlled by internal and external stimuli.
The body – Our bodies are biological machines and are governed by physical laws. We have physical needs, which prompt “vital” movements, such as the beating of our hearts. However, even our most “voluntary” movements are physically predetermined.
Nature – According to Hobbes, the universe is purely physical, and operates like clockwork according to natural laws of motion. The natural world we live in is a part of that universe, and it and its component parts are similarly machine-like. Everything is predetermined, leaving no room for free will, nor for the mind as anything other than the operation of the brain.
Society – Hobbes believed that humans are selfish and exist only to satisfy their individual physical needs. To avoid chaos, we organise ourselves into societies and submit to the rule of law, which serves as a kind of personal protection agency.
The one substance
One solution to Descartes’ mind/body problem (see above: Mind and Body) came from Dutch philosopher Baruch Spinoza. He proposed that reality is a single substance, which has both mental and physical attributes.
Substance and attributes
Spinoza (1632–77) explained his concept of a single universe substance – an idea known as substance monism – in his posthumously published work Ethics. In his formative years, Spinoza had followed Descartes’ view that the physical and mental aspects of the universe were the activities of two substances – the material and the immaterial. However, he rejected this idea later in his life.
In Ethics, Spinoza describes the whole of reality as being composed of one substance, of which both the material and the immaterial are attributes. The human mind is what he calls a modification of this substance conceived under the “attribute of thought”, whereas the human brain is a modification of the substance conceived under the “attribute of extension”. In this way, he avoids the mind/body problem: the two attributes work in parallel and have no interaction at all. For Spinoza, matter and mind are like the shape and taste of an apple: neither gives rise to the other, but each is an attribute of something greater than itself. Interestingly, Spinoza believed that everything in nature has both physical and mental attributes, so even rocks have a form of thought.
More controversially, Spinoza argued that God and substance are identical. Indeed, he uses the words “God” and “nature” interchangeably, and both as synonyms for “substance”. He shared Hobbe’s view that everything is predetermined, but for Spinoza this included God. This is because freedom of choice is a human need, and God – being everything and lacked nothing – has no need for choice. For these and other ideas Spinoza’s work was widely condemned, but it also laid the foundations for much of modern philosophy.
✔ NEED TO KNOW
. Spinoza’s view is often seen as a form of “property dualism”, which states that the world is composed of just one substance, which has both physical and mental properties.
. Pantheism is the belief that God is not distinct and separate from the world, but identical with everything that exists in the universe.
Thought and extension
Spinoza contended that God and nature are identical. He claimed that there is no separate, transcendent creator, but instead that the divine is everything in reality. God manifests in an infinite number of attributes, but only two of these are expressed in our universe: thought (mind) and extension (matter). These are the physical and mental attributes that make up our world, and through them we come to live and understand our nature. They are predetermined and work like clockwork, both being driven by God. These are only two of God’s attributes – others are manifested in worlds beyond are own.
ACCUSATIONS OF HERESY
Spinoza was brought up as a practising Jew, but as he grew up, he increasingly challenged the authority of Judaism, and was eventually banned from the synagogue. His pantheistic claim that God is immanent in everything was later seen as heretical by the Catholic Church, and his works were banned. Although he was often branded an atheist, Spinoza later influenced numerous Christian philosophers, including Soren Kierkegaard.
God – For Spinoza, God is immanent in everything, and has an infinite number of attributes. Two of those attributes constitute our universe: extension (matter) and thought (mind).
Unknown attributes – Since God has an infinite number of attributes, and we can perceive only two, we are surrounded by the mystery of God’s creation.
Extension – The first attribute of substance that makes up our universe is extension, or matter. This is the world of physical things, including their aspects of height, length, and breadth. Matter is like a gear engaged with God, but not engaged with mind, which has a parallel existence to it.
Thought – The second attribute of substance that makes up our universe is thought, or mind. This enables us to understand the world in terms of ideas and concepts and is shared by all other things in the natural world, including rocks and trees. Thought is also engaged with God and works in parallel with matter.
“I say that all things are in God and move in God.” – Baruch Spinoza, Ethics (1677)
The blank slate
In An Essay Concerning Human Understanding, John Locke rebutted the rationalists’ argument that we are born with innate ideas, and so laid the foundations for modern empiricist thought.
British empiricism
Central to the philosophy of John Locke (1632–1704) is the idea that there is no such thing as innate knowledge: at birth, the mind is what he called a tabula rasa, or “blank slate”. When we observe newborn babies, he said, it is clear that they do not bring ideas into the world with them. It is only as we go through life that ideas come into our minds, and these ideas are derived from our experience of the world around us. This idea stood in marked contrast to much contemporary thinking, particularly the ideas of Descartes [see above] and Leibniz, who argued that we are born with innate ideas and that our reason, rather than our experience, is our primary means of acquiring knowledge.
Locke’s idea was not new – it had been defended by Francis Bacon [see above: The Scientific Revolution] and Thomas Hobbes (see above: The Body as a Machine], and even went back to Aristotle. However, Locke was the first philosopher to give a comprehensive defence of empiricism – the idea that experience is our principal source of knowledge. That is not to say, however, that Locke dismissed the importance of reasoning in our acquisition of knowledge. Indeed, he believed that each of us is born with a capacity for reasoning, and that the right education is critical to a child’s intellectual development.
“No man’s knowledge here can go beyond his experience.” John Locke, An Essay Concerning Human Understanding (1689)
🔎 PRIMARY AND SECONDARY QUALITIES
According to Locke, we can only receive information about the world through our senses. This information, he claimed, is of two kinds, and concerns what he called the primary and secondary qualities. An object’s primary qualities, such as its height or mass, are objective, and exist independently of whoever is observing it. However, its secondary qualities, such as its colour or taste, may differ between observers. A ball, for example, may appear grey or multi-coloured to two different observers, but both will agree on its size.
Primary qualities – For Locke, the primary qualities of a thing are its length, breadth, height, weight, location, motion, and overall design.
Secondary qualities – The secondary qualities of a thing are its colour, taste, texture, smell, and sound. These qualities depend on the perceiver’s senses.
Learning the world
Locke claimed that there are two kinds of idea – ideas of sensation and ideas of reflection – and that the latter are made out of the former. In Locke’s words, the objects of the world “cause” ideas of sensation to form in our minds. We then organise these ideas into ideas of reflection.
[1] Blank Slate – At birth, a baby brings no ideas into the world; its mind is completely blank. This means that everything that it will know will come from the world around it. For this reason, Locke claimed that the child should be exposed to the best ideas possible.
[2] Ideas of Sensation – According to Locke, the objects of the world cause ideas of sensation in the infant’s mind. These simple impressions form in the way that light forms images on photographic film: it is a mechanical process that requires no effort on the child’s behalf.
[3] Ideas of Reflection – As the child grows older, it builds ideas of reflection out of its ideas of sensation. From its interactions with other people, and its simple understanding of the qualities of a ball, for example, it can create the idea of “football”. From that, and other simple ideas, it forms the more complex ideas of “teamwork” and “competition”.
✔ NEED TO KNOW
. Although Locke denied the existence of innate ideas, he claimed that we have innate capacities for perception and reasoning.
. In the 19th century, the notion of innate ideas resurfaced. Scholars questioned whether behavioural traits come from “nature or nurture”.
. In the 20th century, Noam Chomsky extended Locke’s idea that we have an innate capacity for reasoning. Chomsky claimed that all humans have an innate ability to acquire language.
An infinity of minds
In his book Monadology, Gottfried Leibniz presented a radical alternative to Descartes’ dualism [see above: Doubting the World]. He argued that the universe is made up of an infinite number of mind-like substances, which he called “monads”.
Monads
Like Descartes, Leibniz (1646–1716) was a rationalist, and believed that knowledge comes primarily from reasoning rather than experience. He argued that the universe is composed of an infinite number of mind-like monads, each of which contains a complete representation of the universe in its past, present, and future states – and that the human mind is one such monad. According to Leibniz, our minds contain every imaginable fact about the universe, and so in theory we should be able to know everything – even the temperature on Mars – through rational reflection alone. We are unable to do this, however, because our rational faculties are too limited, and so, Leibniz argues, we have to “discover” such facts empirically – by doing scientific experiments, for example.
Leibniz distinguished “truths of reasoning” from “truths of fact”, defining the former as truths that we know, if only to a limited extent, through rational reflection alone: these include mathematical truths, such as “two plus two equals four”. Truths of fact, on the other hand, are those that we discover through experience, such as the nature of the weather on Mars.
Properties of monads
Leibniz believed that the fundamental building blocks of the universe had to be indivisible. However, he also argued that since all physical things are divisible, then the true elements of the universe must be non-physical. For Leibniz, these monads are eternal and unchanging, and have no “windows” through which to communicate with each other. Because monads do not exist in physical space, they are similar to the immaterial mind, or soul, that Descartes identified in his dualist theory of the universe.
✔ NEED TO KNOW
. The word “monad” is derived from the Greek word monás, meaning “unit”, which Leibniz borrowed to describe the fundamental units of existence.
. Like Descartes, Leibniz was an accomplished mathematician. He invented the calculus (which Isaac Newton also invented independently) and various mechanical calculating devices.
. Leibniz is often characterised as an optimistic philosopher. He believed that God is supremely perfect, and that ours is the best possible world – one in which the monads exist in harmony.
Facts and ideas
Like John Locke before him, David Hume believed that our knowledge derives primarily from experience. However, he also argued that we can never know anything about the world with certainty.
Natural assumptions
David Hume (1711–76) was primarily interested in epistemology (the nature of knowledge), rather than metaphysics (the nature of the universe). In An Enquiry Concerning Human Understanding, he set out to examine the way that human psychology determines what we can and cannot know, and in particular what we can and cannot know for certain.
Although an empiricist – that is, he believed that experience is our primary source of knowledge – Hume conceded that many propositions, such as mathematical axioms, can be arrived at by reason alone and cannot be doubted: to doubt that 2+2=4 is to fail to understand its meaning. However, he argued that such truths tell us nothing about the world: they simply express relationships between ideas. To gain knowledge about the world we need experience, but Hume argues that such knowledge can never be certain. We are therefore caught on the prongs of a fork: on the one hand, we have certainty about things that tell us nothing about the world; on the other hand, our knowledge about the world is never certain.
Hume argues that it is human nature to make assumptions about the world, especially that it is predictable and uniform. We assume, for example, that when we throw a brick at a window the “brick” causes the window to smash. However, Hume argues that all we know for certain is that throwing a brick at a window is regularly followed by the window smashing. We never perceive causes, he says, but only a “constant conjunction” of events – that is, the regular occurrence of certain events following others. We only imagine a “link” between them.
Hume is not saying that we are wrong to make assumptions – life would be impossible without them. Rather, he is suggesting that we should recognise the extent to which assumptions govern our lives, and not confuse them with the truth.
✔ NEED TO KNOW
. According to Hume, the difference between mathematics and the natural sciences is that mathematical truths are what he calls “relations of ideas”, or necessary truths, whereas scientific truths are contingent, or conditional, “matters of fact”.
. Half a century before Hume, Gottfried Leibniz [see above: An Infinity of Minds] made a similar distinction between truths of reasoning and truths of fact.
. Immanuel Kant and later philosophers distinguished between analytic statements, whose truth can be established by reasoning alone, and synthetic statements, which are verified by reference to the facts.
Hume’s fork
For Hume, there are two kinds of truth: “relations of ideas” and “matters of fact”. The former are true by definition, while the latter depend on the facts. Philosophers call this distinction “Hume’s fork”.
Relations of ideas
Statements of this kind are necessary truths, which means that they cannot be contradicted logically. For example, it is not possible to say that the angles of a triangle do not add up to 180 degrees, or that 2 plus 2 does not equal 4. We can be certain of such truths, but they tell us nothing about the world: they merely express relationships between ideas.
Matters of fact
Statements of this kind are contingent, which means that their truth or falsehood depend on whether or not they represent the facts. For example, it is not illogical to deny the statements “It is snowing” or “I have a cat”. Their truth depends simply on the current state of the weather and whether I own a cat or not.
“Custom, then, is the great guide of human life.” – David Hume, An Enquiry Concerning Human Understanding (1748)
🔎 THE PROBLEM OF INDUCTION
Hume argued that general statements such as “The Sun rises in the east” are logically unjustified because we cannot prove that the Sun will not rise in the west tomorrow. This also means that scientific claims, such as “The Moon orbits the Earth”, are unjustified because we may discover, for example, that the Moon behaves in a different way tomorrow. Such statements are known as “inductions”, because they use the inductive method of reasoning – that is, they make general claims based on a limited number of particular cases.
Similarly, for Hume, we cannot be certain that a croquet ball will behave in the same way as it has in the past.
Shaping the world with the mind
Immanual Kant recognised that while rationalism and empiricism presented opposing claims, both contained elements of truth. He argued that while we know the world through our senses, it is shaped by our minds.
Representations of things
Kant (1724–1804) sought to establish the limits of what we can know about the world. Unlike his predecessor, John Locke, he argued that experience alone was unreliable: not only are we limited to our particular sense organs, when we do perceive something, we only perceive a “representation” of that thing in our minds, rather than see the thing in itself. A rose, for example, may appear red or grey to different animals, and so is only ever seen indirectly, as a construct of our senses.
Kant also argued that our psychological make-up shapes the world we perceive. Our minds are so constructed, he said, that we perceive things in terms of space and time, and that anything outside these parameters is beyond our understanding. He claimed that in a sense we project the concepts of space and time onto the world, and then perceive the world accordingly. A child, for example, learns the concepts “here” and “there” through experience, but it only does so because it innately understands the concept “space”. Likewise, the child learns the concepts “then” and “now” because it has an innate understanding of the concept “time”.
Transcendental idealism
Kant argued that innate concepts are what makes experience possible, and he identified 14 such concepts in all. They are like lenses through which we both project and view the world. Kant was therefore neither a rationalist nor an empiricist – that is, he saw neither reason nor experience as our primary source of knowledge. He described his position as “transcendental idealism”.
🔎 THE NOUMENAL WORLD
Kant compared the way we perceive things to the way a painter presents an image of something. A painting may portray every detail of a scene, but it remains merely a representation of that scene, not the scene itself. In the same way, our perception of an object is a mental representation, not the object as it actually is. We experience only the “phenomenal” world, which is accessible through our senses, but can never have direct access to what he called the “noumenal” world of things-in-themselves.
Categories of understanding
According to Kant, when we perceive an object, we shape it with our innate ideas of space and time: we project these ideas onto the object and then interpret it in those terms. He described space and time as innate “intuitions”, and distinguished a further 12 concepts, or “categories”, which he also claimed we understand innately and project onto what we perceive. He classified these into the four divisions of quantity, quality, relation, and modality.
“Thoughts without content are empty; intuitions without concepts are blind.” – Immanual Kant, Critique of Pure Reason (1781)
[1] Quantity
The categories of Unity-Plurality-Totality enable us to distinguish single things from many things, and to perceive many things as parts of a whole.
[2] Quality
The categories of quality – Reality-Negation-Limitation – give us the notions of something being real or unreal, and that of something having an extent or limit.
[3] Relation
The categories of relation enable us to perceive the properties of an object and to understand its relationships to other objects. These categories are Inherence/subsistence-Causality/dependence-Community/reciprocity.
[4] Modality
The modal categories enable us to know if something is possible or not, whether it exists or not, and whether it is necessary or not. These categories are Possibility/impossibility-Existence/non-existence-Necessity/contingency
Kinds of truth
At the heart of Kant’s transcendental idealism is the idea that it is possible to have knowledge of the world independently of empirical evidence or experience.
A priori and a posteriori knowledge
Before Kant, many philosophers had realised that there are two kinds of truth: necessary truth and contingent truth. A necessary truth, such as “Circles are round”, is one that is true by definition, and so cannot be denied without contradiction. A contingent truth, such as “The sky is blue”, is either true or false according to the facts. Kant introduced two similar distinctions: firstly, between analytic and synthetic statements, and secondly between a priori and a posteriori knowledge.
An analytic statement, like any proposition, consists of a subject and predicate, but its predicate is implicit in its subject. For example, the statement “A square has four sides” is analytic because its predicate (“four sides”) is implicit in its subject (“square”), and so it is true by definition. Synthetic statements, however, have informative predicates, which tell us something new about the world. For example, “This square is red” is synthetic, because its predicate (“red”) is not contained in its subject (“square”).
Kant also identified two kinds of knowledge: a priori knowledge, which is known independently of experience, and a posteriori knowledge, which is known through experience only. These two kinds of knowledge are expressed in analytic and synthetic statements respectively.
However, Kant also claimed that there is a third kind of knowledge: synthetic a priori knowledge, which is both necessarily true (a priori) and informative (synthetic).
Types of statement
An analytic statement is one that is necessarily true, or true by definition, whereas a synthetic statement is one that is either true or false according to the facts. The distinction between a priori and a posteriori knowledge, however, concerns how we come to know the truth – whether by reasoning alone or by reference to the facts.
“All bachelors are unmarried” – this statement is analytic since the term “unmarried” is contained in the definition of “bachelor”.
“2+2=4” – a priori knowledge is independent of experience, and includes analytic statements, but also mathematical propositions such as “2+2=4”.
“All bachelors are happy” – this statement is synthetic, since being happy is not contained in the definition of “bachelor”.
“Water is H2O” – a posteriori statements are dependent on empirical evidence, or experience, and cannot be arrived at through rational reflection.
Synthetic a priori truths
Before Kant, it was assumed that all a priori knowledge must be analytic – that is, if it is known without any empirical evidence, then it cannot tell us anything new about the world. However, Kant claimed that from a priori statements, we can make deductions that are synthetic, and so tell us something about the world.
“The interior angles of a triangle add up to 180 degrees” – This statement is synthetic a priori. It tells us something about a triangle that is not implicit in its definition and is therefore synthetic. However, it is also an a priori truth, since, for Kant, it can be arrived at through rational reflection.
“A triangle is a three-sided shape” – This statement is analytic a priori. The statement as a whole is analytic: the definition of its subject, “triangle”, is a shape with three sides. It is also an a priori truth since we understand it without empirical evidence.
Synthetic a priori judgements
According to Kant, we are born with no knowledge of the world, but we do have innate concepts that enable us to experience the world intelligibly. For example, we have a priori knowledge of the concepts of space, time, and causality, and these enable us to arrive at scientific and mathematical truths that are both synthetic (informative) and a priori (necessary). For Kant, the statement “3+3=6” is a synthetic a priori truth, because it is informative (it says more than “3+3=3+3”) and can be arrived at through reason alone.
Reality as a process
In the early 19th century, German philosophy was dominated by Georg Wilhelm Friedrich Hegel, who regarded reality not only as non-material, but as an ever-changing, dynamic process.
Hegel’s dialectic
Following Kant, many philosophers adopted the view that reality is ultimately non-material. This view, known as idealism, became a feature of German philosophy in the 19th century, and was keenly embraced by Hegel (1770–1831).
For Hegel, since reality is a single entity, the object of philosophical enquiry (the world) and the subject doing the thinking (consciousness) are one and the same thing. This entity is what Hegel calls Geist (“Spirit”). He argues that this Geist is not static but is constantly evolving – unfolding into ever more sophisticated forms of itself. One example of this process is our own understanding of reality – for since we are Geist, advances in our understanding are Geist’s increasing insight into itself.
According to Hegel, this process of Geist’s evolution is dialectical – that is, one in which contradictions appear and vie with each other, and find resolutions that in turn create further contradictions. Every thing (such as anarchy) contains its own opposite (such as tyranny), which combine to form a resolution (such as law) in a process that drives historical progress.
Hegel called these aspects of the dialectic the thesis, antithesis, and synthesis respectively – the synthesis being a new, richer phenomenon made up of the other aspects. However, this synthesis contains its own contradiction, or antithesis, and so becomes a new thesis, which resolves itself in a new, more sophisticated synthesis. For Hegel, the whole of history is such a dialectical process – one that is driven by Geist returning to itself having “emptied” itself into time.
🔎 BEING AND BECOMING
For Hegel, no idea or phenomenon exists in isolation: everything, including human history, is bound up in a dynamic process of becoming. Even reality itself is a process. Hegel explains this by asking us to consider the concept of Being: it is impossible to imagine Being without its opposite, Non-being, which helps to define it. However, Being and Non-being are not merely opposites – they attain their full meaning in the concept of Becoming, which is a synthesis of Being and Non-being.
The dialectic
The progress of our ideas follows a dialectical pattern, as thinkers become ever more conscious of the nature of the Geist. From naïve ideas about the substance of the universe, through various explanations of the nature of reality, our ideas evolve until the Absolute is reached, and Geist becomes conscious of itself as the ultimate reality. According to Hegel, his own discovery of Geist is proof that the Absolute is near.
Thesis – Thales: The truth can be discovered by observing the natural world.
Antithesis – Plato: The natural world is the shadow cast by a higher realm.
Synthesis/Thesis – Aristotle: Observation shows that there is only one realm, which is evolving.
Synthesis/Antithesis – Kant: Knowledge derives from both reason and observation.
Synthesis – Hegel: Reason and observation show that everything is Geist, and that Geist is evolving.
🔎 GEIST AND HISTORY
For Hegel, reality is a process of becoming, although he rejects the notion that the world is made up of matter only. On the contrary, he argues that reality is fundamentally spirit, or Geist, and that matter and mind are aspects of this single, fundamental thing. History, then, is the history of Geist, which is simultaneously evolving and heading towards an end-point. This end-point is what he calls the Absolute: the time when all the contradictions in Geist are resolved and the dialectic comes to an end. At that time, Geist is as it was at the beginning of the dialectic – when, as Hegel puts it, it “emptied out into time”.
The end of history
Having defined reality as an evolving process – one that is driven by the principles of thesis, antithesis, and synthesis – Hegel then argued that history is the evolution of freedom.
Increasing harmony
According to Hegel, reality consists of Geist (“Spirit”), which has emptied itself into time, and history is the process of Geist returning to itself. Because humans are aspects of Geist, human history is also Geist’s history, and so our progress from ignorance to knowledge, and from tyranny to freedom, are Geist’s own evolution. This evolution is characterised by increases in human freedom – because Geist is fundamentally free, and history is the process of Geist manifesting itself.
Since Geist evolves through a dialectical process, so too does human society. At any one time, the tensions within society are caused by a thesis (the status quo) vying with a contradictory position – one that promises to deliver more liberty for the people. This tension is resolved in a synthesis, which is the next stage in human history.
Historical progress
Hegel argued that because reality is not static, but follows a dialectical progression in which Geist becomes more self-aware, history develops in a similar way. He traced the development of history from ancient times, pointing out that in each age, conflicting notions of society have produced a synthesis in which there is an increased consciousness of freedom. From the tyrannies that existed in ancient civilisations, through the evolving systems of government in Classical times, to the overthrow of unjust aristocracies, the process has been towards fairer, more liberal societies. These have culminated in the ideal society – which, according to Hegel, is the Prussian state itself.
“The history of the world is none other than the progress of the consciousness of freedom.” – Georg Hegel, Lectures on the Philosophy of History (1822)
✔ Timeline: Tyranny to the End of History
Tyranny starts. It then flows, hence…
Persia – Ancient Persia is ruled by an absolute monarch, who oversees a strictly hierarchical and authoritarian state, with little concession to individual liberty.
Greece – New forms of society emerge with the establishment of Greek city-states, granting rights to their citizens and even a form of democracy.
Rome – Tensions between the Greek and Persian systems lead to the emergence of Rome as the dominant power that gives rights to its citizens.
Christianity – In contrast to the Roman system, Christianity offers a society based on individual morality and compassion. It is governed by the institution of the Church.
Reformation – Corruption in the Catholic Church and the Holy Roman Empire prompt reforms that create new nation states ruled by the aristocracy.
Revolution – With the power of the Church diminished, the divine right to rule is challenged and the aristocracy is ousted to give power to the people.
Prussian state – The synthesis of aristocracy and revolution emerges in the form of the Prussian constitutional monarchy. The monarch presides over a form of liberal democracy – an ideal state in which freedom is maximised.
The end of history.
Class Conflict in History
As much an economist and sociologist as he was a philosopher, Karl Marx approached the idea of historical progress in terms of the relationship between people and their material conditions.
Materialism and the dialectic
Marx (1818–83) agreed with Hegel’s idea that history is a dialectical process. However, he was uncomfortable with the idealism on which Hegel’s philosophy was based, and eventually dismissed the whole idea of metaphysics. He particularly disliked Hegel’s notion of Geist and focused instead on the socio-economic conditions within societies at each stage in their development. Marx’s dialectic was a materialist one: the prevailing economic structure of each society contains within it its antithesis, and from the tension between the two a synthesis, or different form of society, emerges. Marx saw in this process a means of bringing about change that would eventually resolve all of society’s contradictions. He believed that the perfect society was genuinely possible.
The class struggle
According to Marx, it is not Geist or even the desire for freedom that drives the historical process, but economic forces – specifically, the tensions between those who control wealth and those who do not. Marx claimed that this struggle between the classes have always existed, and that the difference between the master/slave relationships of ancient times and those between what he called the bourgeoisie, and the proletariat is only one of degree. Nevertheless, through the dialectical process, fairer societies have emerged over time. The endpoint of history will be the creation of a classless, “communist” society, in which wealth is distributed fairly.
“The history of all hitherto existing society is the history of class struggles.” Karl Marx, The Manifesto of the Communist Party (1848)
✔ Timeline: Prehistory to Communism
Prehistory starts. It then flows, hence…
Nobles – In ancient civilisations, power and wealth lay in the hands of a ruling nobility, who owned slaves to carry out the necessary labour.
Slaves – The antithesis of the ruling nobility was the class of slaves. They were the property of the nobles but had no property of their own.
Lords – In feudal society, the wealth consisted of agricultural land, which was owned by the lords, but farmed by a class of serfs.
Serfs – Although not owned as slaves, the serfs tended the land for the lords, in return for a small proportion of the produce.
Bourgeoisie – The new ruling class in industrialised society, the bourgeoisie are the capitalist owners of the means of production. They profit from the sale of goods produced by the workers.
Proletariat – The proletariat, or workers, labour in the factories to produce goods for the bourgeoisie’s profit. However, they receive only a minimal wage, rather than a proportional share of the fruit of their labour.
Socialism – One day, the workers will rise up and take control of the means of production. In the ensuing “socialist” society, the state ensures that the workers receive a fair share of the fruit of their labour.
Communism – Eventually the state withers away, leaving a classless “communist” society.
Useful truths
As the United States began to assert its cultural identity in the second half of the 19th century, American philosophers developed a distinctively practical school of thought, which became known as pragmatism.
Pragmatism
The pioneer of this American pragmatism was a mathematician and logician, Charles Sanders Peirce (1839– 1914). Looking at philosophical enquiry from the point of view of a scientist, he was struck by how little practical application it had. Much of philosophy seemed to be a debate about abstract concepts with no connection to the world we live in. To counter this tendency, Peirce proposed a pragmatic maxim: “Consider the practical effects of the objects of your conception. Then, your conception of those effects is the whole of your conception of the object.”
Peirce suggested that to understand the meaning of a proposition we should consider what happens if we accept it and act upon it – in other words, whether it makes any practical difference. From this starting point, he deduced that knowledge consists not of certainties, but of ideas that are valid for as long as they are useful. Science, for example, generates useful ideas that are abandoned or refined when better ones are conceived.
The “cash value” of truth
Peirce’s friend and colleague William James (1842–1910) adopted and developed this pragmatic approach. Truths, he argued, are different from facts, which merely state what is or is not the case. For James, facts are not true in themselves: truth is what emerges if believing them to be true has a “cash value” or makes a practical difference to our lives. Beliefs are not mental entities that are either true or false depending on how well they represent the world: the world is an unpredictable place, and our beliefs are true if they help us to make our way through it. James was a great admirer of Charles Darwin, whose On the Origin of Species (1859) was published when James was still a teenager. Darwin had argued that only the fittest of species survived, and that they did so thanks to their development of superior biological characteristics. For James, something similar can be said about our beliefs – that they become true if they help us to survive and become false if they have no utility.
Belief and action
James notes that we often have no evidence for our beliefs, but act on them anyway to discover if they are true. For example, if someone is lost in a forest and he comes across a path, there may be no evidence that the path will take him to safety, but it is vital that he believes that it does. The example gets to the heart of James’s philosophy: that our beliefs are born of necessity, and their truth depends on how much they improve our lives.
[1] Lost in a forest – If a traveller, lost in a forest, comes across a path, he needs to decide whether or not to take it: it could lead to safety, or it could lead nowhere at all.
[2] A road to safety – If the traveller believes that the path leads to safety, then he should take it.
[3] A road to ruin – If the traveller believes that the path leads nowhere, then there is no point in him taking it.
[4] Justified belief – If the traveller takes the path and finds safety, then his decision was justified: his belief has become true.
[5] Valueless belief – If the traveller stays in the forest, he dies. The truth as he saw it had no value at all.
“Truth happens to an idea. It becomes true, is made true by events. Its verity is in fact an event, a process.” – William James, Pragmatism: A New Name for Some Old Ways of Thinking (1907)
🔎 RELIGIOUS BELIEFS
Broadly speaking, pragmatism is the view that a belief is true if it works in practice – if it is useful and makes a positive difference to our lives. However, it could be argued that by that standard anything could be true, so long as it improves our lives to believe it. Religious beliefs, for example, are seldom held for rational or common-sense reasons: many people are religious because their faith gives them comfort and moral guidance, which are nothing if not “useful truths”.
The pragmatist neither denies nor confirms the objective truth of, for example, the existence of God or the power of prayer, but rather defends the right of the believer to claim it as truth. William James stressed that in examining religious belief it is important to consider the experience of the individual rather than the claims of religious institutions, for it is only the individual who can account for the importance of their beliefs – that is, what use they have in their lives.
The value of truth
With the decline of the Church’s influence in modern industrial society, Friedrich Nietzsche saw the opportunity for a radical re-examination of the basis of truth and morality.
Beyond good and evil
In the 19th century, philosophers inclined increasingly to a materialist view of the world. This was accompanied by an increasing secularism in society, with a growing number of thinkers openly expressing their atheism. Friedrich Nietzsche (1844–1900) lost his Christian faith as young man, and this coloured much of his subsequent thinking. In particular, he identified a problem for modern society: it had inherited the morals imposed by religion, but these now lacked a source that could lend them authority. He felt that moral philosophers and democratic governments were also at fault, since they proposed a morality that applied to everyone alike and failed to accommodate the perspective of the individual.
For Nietzsche, such general systems of morality prevent the individual from living authentically, according to their own standards. He was especially critical of Christian morality, saying that it turns nature on its head by valuing the weak over the strong – advocating humility as a virtue, while threatening vengeful punishment on those who transgress. He called Christianity a “slave morality” – one that equates power with evil, and weakness with good – and claimed that we should instead adopt the morality of the “master”, who sees the world not in terms of good and evil, but in terms of what can either help or hinder us in living life to the full. To move “beyond good and evil” is to abandon Christian ideas, which for Nietzsche are based on the slave’s need to exact revenge on the master: unable to do so in life, the slave invents an afterlife in which the powerful receive their punishment. For Nietzsche, the notion of “free will” has its origin in the desire for revenge. Indeed, all claims to “truth” are shaped in some way by the “will-to-power” – an instinct that drives us to better our condition.
Nietzsche claimed that Christianity should be replaced by a life-affirming morality, and that it should be seen as virtuous for each individual to achieve their full potential. This in turn affects our attitude towards truth, which Nietzsche said depends on perspective. Perspectivism, as he called it, frees the individual to choose which truths to believe, which ones they consider to be life-affirming, and which to ignore.
The will-to-power
For Nietzsche, our conscious beliefs have little to do with the truth, but function rather as masks that hide our unconscious needs and desires. These desires are manifestations of what Nietzsche called the “will-to-power”. The belief in free will, for example, is a mask that hides our need to hold people accountable for their actions: there is no “truth” as to whether they are in fact free or not.
Example: Freedom–Will to Power–Determinism
Freedom: Guilty Verdict – The judge, and the society he represents, hold people responsible in order to exercise control, not because the accused has freely made a choice to do something. The idea of free will is used to justify and facilitate punishment of transgressions.
Will-to-Power: The Hangman vs. Prisoner – A belief in free will enables the hangman to do his job. If he believes the criminal acted freely in breaking the law, then he has no regrets in taking his life.
The criminal, however, may see himself as a victim of circumstance, and so believe he is innocent of his crime. But this merely reflects his desire to escape death.
Determinism: But what is the truth? ask members of the jury.
Claim of innocence – Determinism is the belief that our choices are predetermined, and that free will is an illusion. It is a comforting belief for the family of someone awaiting execution (as they lead the charge of that person being innocent).
✔ NEED TO KNOW
. Standing above the superstitions of society is an ideal individual – an Übermensch (“Superman) – who Nietzsche described in Thus Spake Zarathustra (1883)
. In On the Genealogy of Morals (1887), Nietzsche argued that the moral values of the major religions, and in particular of Judaism and Christianity, are forms of “slave” morality, which venerate weakness and compliance as virtues.
. Much of Nietzsche’s moral philosophy, such as the idea of the will-to-power and the concept of the Übermensch, was hijacked by totalitarian leaders who misconstrued it for their own ends.
. Nietzsche said that religion had been killed. In saying such a thing, he was referring to the rapid secularisation of society that started in the 19th century. Religion, he said, had become increasingly irrelevant in modern society.
Ideas as tools
American thinker John Dewey (1859–1952) belonged to the pragmatic school of philosophy. He argued that ideas are neither true nor false but are tools that either help or hinder us in our lives.
Naturalism
Like the pragmatist C.S. Peirce before him, John Dewey was influenced by the ideas of Charles Darwin, who argued that human beings have evolved through a process of natural selection in the same way as other species. In this sense, Dewey was a “naturalist”, in that he believed that our ability to reason is bound up with our instinct for survival – that we think in order to solve practical problems, rather than to speculate about metaphysical issues. He was influenced by Hegel, who argued that all human activities – including science, art, and philosophy – are shaped by history, and so can only be understood in their particular historical contexts.
Instrumentalism
Dewey sometimes referred to his position as “instrumentalism”, by which he meant that ideas should be seen as tools and should be judged according to how useful they are at solving specific problems. He contrasted this with the idea that thoughts are representations of the world. Additionally, Dewey believed that just as humans evolved by adapting to changing environments, the same is true of ideas. He argued that theories are neither true nor false, but only efficient or inefficient at explaining and predicting phenomena. Like his fellow pragmatists, he thought that the important question when assessing an idea is not “is this the way things are?” but “what are the practical implications of this perspective?”
The process of inquiry
Dewey’s view broke away from centuries of thinking about the nature of knowledge. Since Descartes, rationalists had argued that we are born with innate ideas, and since Locke, empiricists had argued that ideas are copies of impressions generated by experience. Dewey believed that both traditions were wrong and had failed to appreciate that our ideas serve to manipulate the world. Indeed, he rejected the phrase “theory of knowledge”, preferring “theory of inquiry” instead – inquiry being an active, human practice.
Dewey distinguished three phases of inquiry: firstly, we encounter a problem and react to it by instinct; secondly, we isolate the information that is relevant to the problem; and thirdly, we imagine solutions to the problem and then act on our favoured option. For Dewey, philosophers had wrongly isolated the third stage of this process, imagining that ideas can be separated from the world in which problems arise. Instead, he claimed that knowledge is functional, and is only valid as a basis for human action.
🔎 DEWEY AND DEMOCRACY
Dewey was a passionate believer in democracy. He argued that democracy is only possible in a society in which people are properly educated but felt that too many schools did little more than rear children to fit in with the social order. Instead, he proposed that schools should enable children to discover their own talents, and to find their own unique place in the world. Only then, he argued, could children grow up and truly participate in democracy, for only then could their opinion be said to be fully informed. Effectively, he thought that schools should teach children how to live.
Dewey also supported women’s emancipation and racial equality. As he wrote in Democracy and Education (1916): “If democracy has a moral and ideal meaning, it is that a social return be demanded from all and that opportunity for development of distinctive capacities be afforded all”.
Useful thinking
Dewey rejected the traditional “correspondence” theory of truth, according to which an idea is true if it corresponds to reality. Instead, he argued that ideas are tools that we use to help us live our lives. He redefined “truths” as “warranted assertions”, arguing that we hold them for as long as they are helpful.
. Toolbox of ideas – According to Dewey, ideas are tools that we select to resolve “felt difficulties” in the world. These difficulties are practical in nature and arise from our need to adapt to our environment.
. Testing ideas – We test our ideas by using them in the world. If they prove to be useful, then we accept them as provisional judgements. If they are unhelpful, we set them aside.
. Improving ideas – Since our judgements are functional, they can always be replaced. This happens when, in Dewey’s terms, a better tool comes along. A new tool may serve our needs more efficiently than one we are using already, but it too can be replaced in the future.
“… the only ultimate value which can be set up is just the process of living itself.” – John Dewey, Democracy and Education (1916)
This concludes the narrative for the page ‘Foundations in Philosophy’. Amendments to the above entries may be made in the future.
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