Daily Archives: February 15, 2023

Arts, Philosophy, Science

Philosophy: Facts and ideas

REASON AND EXPERIENCE

Intro: 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 (1711–1776) 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 a brick is thrown 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 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.

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.

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”.

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 may also behave 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 or events. There are different types of inductive argument which will be examined in detail in a future entry.

NEED TO KNOW

. According to Hume, the difference between mathematics and the natural sciences is that mathematical truths are what he calls “relations or ideas”, or necessary truths, whereas scientific truths are contingent, or conditional, “matters of fact”.

. Half a century before Hume, Gottfried Leibniz made a similar distinction between truths of reasoning and truths of fact. Leibniz was an accomplished mathematician. He invented calculus (which Isaac Newton was also instrumental in) and was characterised as an optimistic philosopher. He believed that God is supremely perfect, and that ours is the best possible world – one in which the modern “monads” exist in harmony. The word “monad” is derived from the Greek word monas, meaning “unit”, which Leibniz borrowed to describe the fundamental units of existence. He distinguished “truths of reasoning” from “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.

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Britain, Defence, Government, National Security, Society, Technology, United States

Menacing spies in the sky

NATIONAL SECURITY

ABOVE our heads – some 80,000 feet up – a high-tech tussle is under way, with our most closely guarded secrets and our national security at stake. The shooting down of a number of intelligence balloons in recent days seems closer to a fictional tale rather than the serious threat they pose.

Four mysterious aircraft have been shot down in just nine days over North America, three by the US Air Force and one by the Royal Canadian Air Force.

The fictional perspective was primed when an American general sparked a storm of speculation when he said that he was not excluding extra-terrestrial origin for these intruders. General Glen VanHerck, commander of North American Aerospace Defence Command, when asked about the possibility of aliens, said: “I haven’t ruled out anything at this point.”

For these are – quite literally – unidentified flying objects. The language used to describe them recalls the unexplained sightings that, for decades, have puzzled even seasoned observers. UFO enthusiasts are enthralled. In 2021, the Pentagon set up the Airborne Object Identification and Management Synchronisation Group to investigate more than 100 incidents.

One of the aircraft, downed last week over Alaska, was described as “cylindrical and silverish gray”, about the “size of a small car” and with “no identifiable propulsion system”. Another, brought to earth on the US-Canadian border, was a “small, cylindrical object”.

Such intruders may also have crossed British territory. Rishi Sunak, newly enthused by military matters, says we can and will shoot them down if necessary.

Defence Secretary Ben Wallace has ordered a review. For now, the questions are multiplying. Are they Chinese? The West seems to think so. The regime in Beijing has protested about the downing of two of them – just peaceful weather balloons, it insists.

Security officials in the West say that China’s stratospheric surveillance programme has operated for many years, and over five continents. It is the brainchild of the Strategic Support Force, a secretive component of the People’s Liberation Army. So, why now? Why have we not noticed this before?

The short and probable answer is that we weren’t looking. These balloons and drones move incredibly slowly at great heights. Our air-defence radar works at lower altitudes. Our missile defence-systems track fast-moving rockets. US officials are now scouring data collected in previous years for signs of intrusions that they may have missed. So far, the Pentagon says, four previous instances have been identified.

In any case, malevolent intruders can easily be missed amid the thousand of innocent weather balloons launched every day. Gathering meteorological data provides perfect cover for covert missions. China counteracts claiming that the US has repeatedly sent spy balloons into Chinese airspace. The Americans deny this.

THREATENING

THE question looms as to why China would invest so much in these missions when it has more than 260 spy satellites? Being only 15 miles above the earth’s surface – satellites are seven times higher – gives them a clear edge in taking photographs and hoovering up electronic information, such as the ultra-sensitive “friend-or-foe” systems that prevent us shooting down our own warplanes.

These satellites can loiter over sensitive military installations, such as the RAF base at Boscombe Down in Wiltshire, used by American spy planes. Gathering information about the temperature and density of the air at high altitudes could also give a crucial advantage to missile-guidance systems. These spycraft may also be sent to test national defences.

Most worryingly, China published in 2018 a video showing a balloon being used as a platform to launch hypersonic weapons. These can travel vast distances at high speed, evading our defences and delivering either nuclear warheads, or electromagnetic pulse blasts that devastate all electrical and electronic devices.

What keeps these machines aloft and on course, thousands of miles from home, nothing is said.

Some clues, however, may come from here in Britain. We have Stratospheric Platforms, a company that offers internet access from a drone that can stay in the atmosphere for a week at a time, powered by a hydrogen engine. Another British start-up, Avealto, has a solar-powered craft in orbit that targets the same market.

Speculation abounds about even more advanced technologies. Aviation experts are eagerly awaiting news from the wreckage of the recent devices shot down.

Could, for example, the Chinese have cracked the difficulties of “ion propulsion”, which uses blasts of electrically charged air to stay aloft, and requires no combustion or moving parts like propellers or jets?

Prototypes of aircraft using this technology already fly, but they use too much electricity to be viable. Or so we think.

Whatever the case, the wreckage recovered from the recent incidents’ will be eagerly inspected by American military technologists hoping to gain an edge in the battle against spy wars in the sky. The results of their investigations will be classified secret. Why give clues to the enemy?

One thing in this extraordinary story is clear. These balloons are far from innocent and have caught the guardians of our security napping. Vigilance has been poor.

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