Monthly Archives: February 2023

Arts, Philosophy, Science

Philosophy: The blank slate

INNATE IDEAS

Intro: 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.

“No man’s knowledge here can go beyond his experience.” – John Locke (1689)

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 new born 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 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 and Thomas Hobbes, 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 principle source of knowledge. That is not to say that Locke dismissed the importance of reasoning in our acquisition of knowledge. He believed, too, that each of us is born with a capacity for reasoning, and that the right education is critical to a child’s intellectual development.

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:

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.

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.

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”.

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 multicoloured 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.

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 nuture”

. 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.

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Arts, Christianity, Culture

The Old Testament Book of Numbers: Water from the Rock

CHAPTER 20

THE previous narrative on the Book of Numbers (see article) stated that it might better have been called The Book of Warnings. Events in Numbers primarily focus on Moses’ authority and leadership and God’s care for the Israelites.

The second narrative from the Book of Numbers is based on Chapter 20, verses 1–13.

Moses’ patience snaps at last

Moses sounds like an exasperated parent of a demanding child, frustrated, angry and giving in at the same time: “Oh, all right then – have it!”

Early in the journey, Moses had struck the rock at Sinai and tapped into an underground aquifer (Exodus 17: 1-7). Now at Kadesh, near the end of the journey, he is told to speak to the rock, but he strikes it as well.

God’s reaction, to bar Moses from Canaan, seems harsh. But Moses’ words are revealing: “Must we bring you water out of this rock?” Although renowned for his humility (12:3), he is not now acting as God’s servant but as his deputy, as he decides on the method he will use to bring about God’s will.

The balance of doing God’s will in God’s way is always difficult to achieve. Moses was not alone in failing, and the example is a salutary one for Christians eager to see “results”; ends do not justify means.

He may also have assumed that because God acted in one way in an identical situation before, he would so the same second time around. It would be more true biblically – and in experience – to say that God rarely works in the same way twice. He shows his holiness – his supremacy – by varying his methods and seeking his people’s trust (Deuteronomy 32:51). As detailed in the previous narrative, hardship is never a reason to question God but an opportunity to trust him. It’s a major lesson from the Old Testament Book of Numbers for today.

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Environment, Research, Science

Migrating animals: How do they find their way?

ETHOLOGY

Intro: The ability by some animals to find their way when migrating over long distances intrigues and amazes us. The puzzle of how they do this is difficult to solve and we are only really just beginning to find answers

SOME of the migratory habits of animals are truly astonishing, not least because without our own navigational aids, our compasses and our GPS systems, we very easily get lost ourselves. Arctic terns leave their northern breeding grounds in and around the Arctic Circle towards the end of the summer to fly south all the way to the Antarctic coast, arriving in time for the onset of summer in the southern hemisphere, and then fly all the way back to the Arctic to breed the following spring. If the terns flew directly between their two destinations, this would involve journeys totalling over 32,000 km (20,000 miles), but they actually adopt much more convoluted routes, increasing the distances they cover by tens of thousands of miles. Yet after covering such enormous distances, the terns often return to the exact spot where they bred the previous year.

Atlantic salmon spend most of their adult lives in the ocean before returning to the same river where they were born, and usually to the same stretch of that river, to spawn. Some monarch butterflies are involved in a circular migration – which takes several generations to complete, travelling from southern Canada to overwintering sites in central Mexico while every year, millions of Christmas Island crabs travel from the forest in the interior of their Indian Ocean island to the coast to breed. Several species of frogs and toads engage in similar annual mass migrations, and sea turtles such as loggerheads and leatherbacks give the impression of being engaged in a lifelong migration, swimming for what can be thousands of kilometres between breeding grounds on beaches and feeding grounds in the distant ocean.

Navigating animals

These birds, fish, butterflies, crabs and turtles provide a few examples from among the thousands of species of animals that engage in migratory behaviour of one sort or another. Charles Darwin thought that animals, and to some extent humans as well, possessed an instinctive ability to orientate themselves in their surroundings, which they could use to navigate by dead reckoning, but he could not be any more specific about how this ability worked. Beginning in the 1910s, the Austrian animal behaviourist Karl von Frisch carried out experimental research on honeybees, which showed that their primary means of navigation involved using the position of the Sun to orientate themselves, but that they could also detect and follow the pattern of ultraviolet light in blue skies, which is caused by polarisation and is invisible to human eyes. On cloudy days, Frisch found that the bees could also make use of the Earth’s magnetic field to find their way when the Sun and polarised light were not visible. He would also be the first to describe the so-called waggle dance that the bees engaged in as a means of communicating the location of a source of nectar they had found to other bees in a hive.

Since Frisch’s work, which earned him a Nobel Prize in 1973, other animals, such as sea turtles, have also been found to be able to detect the Earth’s magnetic field. Homing pigeons, which can return to their own lofts after being released hundreds of kilometres away, appear to use the magnetic field as one of a range of navigation techniques. Attempts have been made to discover how pigeons detect the magnetic field, which is actually very weak, and while we do not know for certain, one theory suggests they somehow make use of particles of magnetite, a highly magnetic mineral of iron oxide found in the upper part of their beaks. Even so, it remains a mystery how the navigational information that may be gained in this way is passed to the brain and processed.

Homing pigeons can switch between different methods of navigation as circumstances dictate, sometimes following known landmarks, such as coastlines, rivers and roads, while at others navigating by the Sun and stars. When it is too dark or cloudy for them to see the sky, they can fall back on finding their way by following the magnetic field. Researchers at the University of Texas who monitored the brain activity of pigeons while they were subjected to a moving magnetic field came to the conclusion that, as well as having compasses in their heads, the pigeons somehow constructed maps in their brains as they went along, so when they ended up in a place they had never been before they could head straight for home. We may like to think of ourselves as rather more intelligent than pigeons, but, for all our superior brainpower, we can’t do that.

Alternative theories

Research into the ability of European robins to use the Earth’s magnetic field to navigate suggests that the mechanism involved may work at a subatomic, or quantum, level. If this proves to be the case, then it would go some way to explaining how animals can detect and make use of the natural magnetic field, which is far too weak to provide enough energy to power any molecular chemical reactions. Magnetoreception, as this ability is known, appears to function through the eyes of the robin, so it is possible that light provides the energy required to activate so-called radical pairs, subatomic charged particles that are small enough to be influenced by the low levels of magnetism and may create some form of navigational signal that is then passed to the robin’s brain via the optic nerve.

See also:

. Book Review – ‘Greenery: Journeys In Springtime’

. Science Book

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