Philosophy 100 Essential Thinkers

by Philip Stokes

The two great superpowers of the twentieth century, the USA and the USSR, were born of the philosophical writings of Tom Paine and Karl Marx respectively. The modern information age would never have been possible without the work of the great logician Frege. Female suffrage was taken seriously only after Wollstonecraft. The Enlightenment stood in need of a Voltaire, Einstein needed Newton and Newton, in turn, relied on Aristotle. The history of social, political and technological change is inextricably bound to the history of thought.

Thales, probably born somewhere around 620 BC is mainly remembered as the presocratic philosopher who claimed that the fundamental nature of the world is water.

Philosophical certainties could not be had, according to Xenophanes, for even if we chance to hit upon the truth, there is no way of knowing for certain that things are as we think they are.

It is chiefly through the influence of Socrates that philosophy developed into the modern discipline of continuous critical reflection. The greatest danger to both society and the individual, we learn from Socrates, is the suspension of critical thought.

Much of our knowledge of Greek thought is due to Cicero’s translations and he remains a primary source for students of Hellenistic philosophy.

The philosophical vocabulary invented by him is responsible for Latin becoming the primary philosophical language over Greek: despite the invention of modern languages, Latin remained the primary language of philosophy right up until the Renaissance.

One particular passage to Seneca’s grieving mother is illustrative of his sermonising style: ‘You never polluted yourself with make-up, and you never wore a dress that covered about as much on as it did off. Your only ornament, the kind of beauty that time does not tarnish, is the great honour of modesty. So you cannot use your sex to justify your sorrow when with your virtue you have transcended it. Keep as far away from women’s tears as from their faults’.

‘The happiness of your life depends on the quality of your thoughts’

Prior to Copernicus, astronomers had favoured the view, following both Aristotle and Ptolemy, that the Earth was at the centre of the universe, with both the stars, sun and the moon revolving about it. Known as the Ptolemaic system, this view was wholly in keeping with many theological teachings, in which the universe is seen to be created by God for the express purpose of man. The effect of Copernicus’ work was to turn all this on its head.

The effect of the original ‘Copernican Revolution’ on the development of Western thought, both philosophical and scientific is difficult to exaggerate. It gave birth to the scientific age and helped remove many of the superstitious and ignorant beliefs so typical of the time. It would, for better or worse, lead to the decline of the power of the church, and to a new age of scientific inquiry and invention.

In The Prince, Machiavelli considers how best a leader can achieve his ends once he has determined that the ends he has identified are worthwhile. Never has the phrase ‘the ends justify the means’ been more appropriately applied than it is to Machiavellian technique.

Machiavelli thinks there are three primary political ‘goods’: national security, national independence, and a strong constitution. Beyond this, he is almost entirely concerned with practical questions of how to go about securing political success.

The heart of Machiavelli’s teachings consists in the manipulation of others, including the populace, for power. To this end, although Machiavelli does not teach that virtue is good in itself, it can often serve one’s political ends to appear to be virtuous. This is perhaps the doctrine that has caused most outrage against Machiavellian thought.

Without doubt, The Prince is a work meant only for those that have the fibre to take this fact, surely true, however unpleasant, seriously.

Machiavelli has no time for tyrannies, not because people have an inalienable right to freedom, but because tyrannies are less stable, more cruel and more inconstant than governments held in esteem by a reasonably content population.

True religion, Erasmus insists, is a form of Folly, in the sense that it is simplistic and direct, not convoluted with unnecessary sophistications and dogmatic doctrine.

Moreover, what would later be Newton’s celebrated First Law of Motion was directly taken from Galileo’s principle of inertia, namely that a body moves in a straight line with uniform velocity unless acted upon.

In an analogy reminiscent of Newton’s first law of motion, which says matter will behave in a uniform way unless acted upon, Hobbes believes the natural state of man is one of war and strife, unless acted upon and governed by the rules of social living. Only a covenant kept by the rule of the sword can keep man from falling back into his natural state. Without the covenant, Hobbes tells us, society would disintegrate and it would be ‘a war of every man, against every man’ and the result would inevitably be that the life of man would be ‘solitary, poor, nasty, brutish and short’.

Every man operates, says Hobbes, according to a natural law of self-preservation. We each naturally want what is good for ourselves, and the covenant ensures that this can only be gained by taking into account the good of others.

French philosopher and mathematician, Descartes is often called the father of modern philosophy. Known to physicists as the discoverer of the law of refraction in optics, Descartes’ most famous work is in philosophy. Meditations on First Philosophy set the agenda for speculation in the philosophy of mind and epistemology for at least the next 300 years.

program. Rather than attempt to examine and order each belief in turn, a task impossible to contemplate, he decides to examine his beliefs against a method of doubt. The method of doubt consists in questioning the source of his beliefs and asking whether that source is infallible. If not, he can be sure that any belief from that source cannot be relied upon to provide the foundations of knowledge.

That which appears evil does so only because we lack the understanding to see the bigger picture, the chain of causes that make all events a necessary part of divine reality.

For Locke, there could be no innate knowledge: rather, everything we know must be derived from experience, through the actions of the physical world on our sense organs. This is the view now known as empiricism, a view still central, in essence if not detail, to the philosophies of Quine and other modern thinkers.

Hume’s scepticism does not stop there. He regards human belief in causation as just a special case of a more general psychological trait: inductive reasoning. Inductive reasoning is the process that leads us to make generalisations from observing a number of similar cases. For example, having observed many white swans but no black swans, one might seemingly be justified in the conclusion that ‘All swans are white’. Equally, being aware that men often die, we conclude ‘All men are mortal’.

But such generalisations go beyond what is given in experience and are not logically justified. After all, black swans were found in Australia, and there is always the logical possibility of coming across an immortal man.

Since all scientific laws are merely generalisations from inductive reasoning, this so-called ‘problem of induction’ has been an urgent one for philosophers of science. Trying to show how induction is justified has taxed them throughout the 20th century. Karl Popper is notable for offering the most promising solution to Humean scepticism.

The Encyclopedia was to become the subject of further controversy for Voltaire, as it was considered to be a challenge to faith by encouraging people to look to the power of reason.

He did not write his first independent work until he was nearly forty years old, but soon became famous on its publication.

Popular myth has it that the Königsberg professor, an inveterate bachelor, was so regular in his daily constitutional that housewives would set their clocks by the time at which he passed their windows.

Natural selection thus has two components. First, the minor differences that exist between individuals, and second the principle of inheritance that passes these differences down through the generations.

Critics have complained that evolutionary theory is scientifically vacuous because it is incapable of refutation. If true, Darwin’s idea would be less of a theory and more of a blind faith. However, Darwin himself was clear about what could falsify the theory. ‘If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down’. So far, no alternative theory has provided the required demonstration to meet Darwin’s challenge.

Bergson’s philosophy proceeds from a fundamental distinction between life force, the ‘élan vital’, and matter. These are really two conflicting impulses of the universe. The one, the urge to continually create and diversify, the other an entropic compulsion to make everything uniform, to dissipate energy and resist the flow of life. These two conflicting forces are reflected in Bergson’s theory of knowledge.

The intellect attempts to deal with the continuous flow of experience by breaking time up into discrete ‘moments’. But Bergson claims the discretion is artificial. In experience there is a constant interpenetrability of past and present. Change is continuous and dynamic, not discrete and static.

Bergson rejects any kind of ‘teleological’ explanation of evolution, such as that found in Aristotle’s idea that everything is striving to fulfil a pre-ordained purpose. This sort of conception Bergson calls ‘inverse mechanism’ – the idea that everything is determined not by prior cause but by some future potentiality. Bergson rejects both as deterministic.

The ‘élan vital’ is the driving force of novelty, as seen in works of Art and Literature. Such works, Bergson maintains, are always a product of prior influence, and yet they are much more than just the sum of their parts. They embody a unified idea which can only arise from the intuition of the artist.

Peirce sees knowledge as a means of stabilising our habitual behaviour in response to doubt

A belief, as Peirce understands it, is not some intellectual disposition to assent to a proposition, but a behavioural habit manifest in action.

According to James, empiricism has laid too much emphasis on the elements and origins of experience, without attending to the importance of how those elements, or ‘sense-data’, are related and used to predict future experience.

James insists all knowledge is pragmatic – in other words, something is either true or right just insofar as it has a successful application to the world.

Unlike having the choice of calling something true or false a forced issue is, James says, akin to being asked ‘either accept this truth or go without it’. No middle ground is possible.

James thinks the choice whether to believe in God or not is a ‘forced’ issue of this kind. To back agnosticism or scepticism in this case is tantamount to telling others that ‘to yield to our fear of being in error is wiser and better than to yield to our hope that it may be true’.

Since a life of religious belief has a positive effect of bringing discipline, motivating force and strength into our character, James considers that it does indeed have a pragmatic effect, to make our lives go better than if we do not believe.

Freud claims to have proven that the conscious mind, or the self, is not ‘master of its own house’, as all rationalist and Cartesian philosophies presuppose.

Jung went on to distinguish between a number of different personality types, and invented the terms ‘introvert’ and ‘extrovert’ to describe two of the most basic.

According to Jung, introverted personalities were those, such as himself, whose ‘ego’ was turned more towards the internal and unconscious, whereas extroverts were orientated more towards outer reality and external activity.

Jungian psychology has led to the development of highly accurate personality profiling, such as the Myers-Briggs Type Indicator, and contributed to the development of psychometric testing, the use of which is now widespread in human resources departments for assessing the suita-bility of candidates for employment.

Keynes’ theory was seen at the time as the answer to Marx’s prediction that the boom and bust cycle of capitalism would inevitably lead to socialism. Keynes showed how government intervention could lead to a stable free market economy.

Kierkegaard rails: ‘Each age has its characteristic depravity. Ours is perhaps not pleasure or indulgence or sensuality, but rather a dissolute pantheistic contempt for individual man’.

We are, at every turn, faced with the need to make decisions. Choice is our starting point, constant companion, and heaviest burden.

In his Journals Kierkegaard complains, ‘What I really lack is to be clear in my mind what I am to do, not what I am to know… the thing is to find a truth which is true for me, to find the idea for which I can live and die’.