The First Relativists in Philosophy
Scepticism as a philosophy was launched on its long and
influential career by one of Alexander the Great's soldiers
Excerpt from Bryan Magee's, The Story of Philosophy
In the broadest sense of the word “scepticism” there had long been a certain tradition of it in Greek philosophy. Xenophanes had taught that, although we can always learn more than we know, we can never be sure that we have reached any final truth. Socrates said that the only thing he knew was that he did not know anything. However, Socrates did at least believe knowledge was possible and, what is more, he was bent on acquiring some, while Xenophanes believed that we could lessen the degree of our ignorance if we made the effort. Both men took a positive attitude towards enquiry and the possibility of learning.
ARGUING BOTH WAYS
The first person to make scepticism the be-all and end-all of his thought – to adopt it as being itself a philosophy, so to speak, and one consisting of an active refusal to believe anything – was Pyrrho (c. 365-270 BC). He launched a whole school of philosophers that became known as Sceptics; and their brand of systematic, all-embracing philosophical Scepticism is to this day sometimes referred to as Pyrrhonism.
Pyrrho had served as a soldier with Alexander the Great and had campaigned with him as far afield as India. Seeing such a huge diversity of countries and peoples seems to have impressed on him the diversity of opinions that are to be found among human beings. For almost everything believed by the people in one place there seem to be people somewhere else who believe the opposite. And normally the arguments are equally good on both sides – or so it seemed to Pyrrho. All we can do is go by things as they appear to us: But appearances are notoriously deceptive, so we should never assume the truth of one explanation rather than any other. The best thing was to stop worrying and just go with the flow, that is to say, swim along with whatever customs and practices prevail in the circumstances we happen to find ourselves in.
Pyrrho had a pupil, Timon of Philius (320-230 BC), who supported this attitude with more substantial intellectual arguments. In particular he pointed out that every argument or proof proceeded from premises, which it did not itself establish. If you tried to demonstrate the truth of those premises by other arguments or proofs then they had to be based on undemonstrated premises. And so it went ad infinitum. No ultimate ground of certainty could ever be reached.
After Timon's death his successor, Arcesilaus (315-240 BC), took over the leadership of Plato's Academy, which then remained in the hands of the Sceptics for two hundred years. Arcesilaus had two main teaching methods: one was to expound equally powerful arguments on both sides of a question; the other was to offer to refute any case put by one of his students. His successor as head of the Academy, Carneades (214-129 BC), made a great stir on his visit to Rome by giving a series of public lectures, in the first of which he forcefully expounded the views of Plato and Aristotle on justice, and then in his second lecture refuted everything he had said in the first.
NO ULTIMATE CERTAINTY
Scepticism has had a permanently important part to play in the history of philosophy, from that day to this. Chiefly it is because certainty is simply not available at the level of argument, demonstration or proof – although it was not until the 20th century that this became generally acknowledged, so the pursuit of certainty was destined to play a centrally important role in the historical development of philosophy.
What a valid argument proves is that its conclusions follow from its premises, but that is not at all the same as proving that those conclusions are true. Every valid argument starts with and “if”: if p is true then q must be true. But that leaves open the question of whether or not p is true. The argument itself cannot prove that, because it has already assumed it, and to have assumed already what it sets out to prove would be to move in a vicious circle. So every “proof” rests on unproven premises; and this is as true in logic, mathematics, and science as it is in everyday life. Even so, it does not follow from this that we have no better grounds for any one set of beliefs than for any other: to say that would be untrue. However, the working out of these tricky distinctions was to be a long and troublesome business in the history of philosophy.
The most famous Sceptical philosopher of more recent centuries is the Scotsman David Hume. He qualified his own Scepticism by pointing out that to live at all we have perpetually to make choices, decisions, and this forces us to form judgments about the way things are, whether we like it or not. Since certainty is not available to us we have to make the best assessments we can of the realities we face – and this is not compatible with regarding all alternatives with equal scepticism. Our Scepticism therefore needs to be, as he put it, mitigated. It is indeed doubtful whether anyone could live on the basis of complete Scepticism – of if they could, whether such a life would be worth living. But this refutation of Scepticism, if refutation it is, is not a logical argument.
In practical life we must steer a middle course between demanding a degree of certainty that we can never have and treating all possibilities as if they were of equal weight when they are not.