As well as this radical ‘departmentalizing’ of knowledge, Aristotle imports a further difference. Whereas Plato focuses relentlessly on the individual knower, Aristotle widens his epistemological view to take in many aspects of the social production of knowledge. It is not for nothing that ‘science’ is more appropriate to Aristotle’s discussions of knowledge than to Plato’s. Aristotle is aware of the way that the development of a science, such as biology, requires research and observation from many people, and also that the single investigator does not reinvent the wheel every time, but relies on others’ results and data and, more importantly, on their questions and setting of the problems. He himself begins his enquiries in a number of fields by first canvassing views on it that are reputable and widely held, or put forward by philosophers or other investigators. It is by entering into this tradition of previous enquiry and exploring the problems that it has thrown up that the investigator can make progress.
Hence Aristotle can distinguish (though it would have been nice if he had done so more clearly) between different aspects of the development of a body of knowledge. The data and observations a science relies on, built up by the co-operative activities of many people, are material for a science, not science itself. Pieces of information do not constitute knowledge until they are fitted into and form part of a structured system. Hence before they amount to knowledge, the results of research and observation must be given a place within the appropriate structure. In the Posterior Analytics this structure is laid out very rigidly, and the influence of the mathematical model is very obvious. The first principles of a science must be true, primary and immediate, hold necessarily and be explanatory of the results that they are the first principles of. Much effort has gone into exploring ways in which a science like, say, biology could fit such a model, and it is generally agreed that the model is unsuitably rigid for many Aristotelian sciences. The overall point is not lost, however: empirical research is needed to gather any information worth knowing, but knowledge comes only when we see how it fits into a formal explanatory structure.
Both Plato and Aristotle have an extremely ideal model of understanding. Neither doubt that knowledge is possible in principle, though for Plato particularly the conditions become very idealized and removed from everyday life. Of course, given that they are working with the expertise model, the idea that knowledge is possible is not very radical. But what they are claiming is that we can have knowledge not merely of humdrum matters but of philosophically challenging and worthwhile subjects. Some version of this claim is common in most ancient philosophical schools.
This is not the only approach to knowledge, however; we find very different ones. The most radical of these is traced in part to Socrates and in part to Pyrrho, a later philosopher who also wrote nothing. This is ancient scepticism (making Socrates one founder of scepticism). Unlike modern scepticism, the ancient movement does not limit itself to denying that knowledge is possible, leaving us with true belief. Ancient scepticism is as concerned with holding beliefs as with knowledge, and is best thought of as an intellectual position concerning the powers of reason, one far more radical than modern scepticisms.
The sceptic begins like everyone else, by searching for truth and for knowledge. This he does by investigating, querying others’ reasons for what they claim, and looking for supporting reasons for positions of his own. So far there is no disagreement with the basic idea that knowledge requires the giving of a reasoned account. Knowledge of any kind worth having (that is, not knowledge of everyday bits of information) requires that you be able to give satisfactory reasons for what you claim. What distinguishes the sceptic from other philosophers is just that he never regards himself as having got to that point. The Greek term skeptikos means, not a negative doubter, but an investigator, someone going in for skeptesthai or enquiry. As the late sceptic author Sextus Empiricus puts it, there are dogmatic philosophers, who think that they have found the truth; negative dogmatists, who feel entitled to the position that the truth cannot be found; and the sceptics, who are unlike both the other groups in that they are not committed either way. They are still investigating things.
Pyrrho of Elis (c.360 – c.270 BC) is, like Socrates, an influential philosopher who inspired others but wrote nothing himself. His life is even more elusive than that of Socrates, and unlike him he left no visual image.
Originally a painter, Pyrrho at some point was influenced by various philosophical schools. He accompanied Alexander the Great on his conquest of northern India, where he encountered Indian ‘gymnoso-phists’ or naked wise men. It has been claimed that this encounter was decisive for his own philosophical stance, and similarities have been claimed between reports of his arguments and early northern Indian Buddhist texts. The Greeks, however, found no problem in interpreting Pyrrhonism in Greek terms, especially as Pyrrhonists always argue against the views of others, and so developed a repertory of attacks on existing philosophical theories.
Pyrrho himself impressed others by the example of tranquillity and impeturbability he gave in refusing to commit himself to any dogmatic belief. Stories about him abound, but are mostly hostile jokes to the effect that he suspended judgement in everyday matters, thereby making himself ridiculous. Other stories say that he lived a respectable life and that Elis exempted philosophers from taxation in his honour. His pupil Timon wrote satires against dogmatic philosophers, and also prose accounts of Pyrrho’s arguments which, though problematic, show them as forerunners to the later versions of these arguments, especially those found in our main sceptical text, Sextus Empiricus’ Outlines of Pyrrhonism (of uncertain date but probably second century AD).
Why the problem? Surely if you investigate you will turn up some results that can count as knowledge or at least as belief. Sceptics think that, while we want to think this, it will always turn out to be rash (or ‘precipitate’) assent: we committed ourselves too soon. Real inquiry, thorough investigation, will reveal that the situation was more complex and problematic; we turn out never to have reason to commit ourselves one way or the other, and so end up suspending judgement – that is, having a detached and uncommitted attitude to whatever the issue was.
At first this sounds ridiculous, indeed unserious. Does the sceptic really hold that we can never establish what time it is, that the sun is shining, that this is bread and not grass? This is an ancient reaction, but a mistaken one.
Pyrrho, the founding figure of one branch of scepticism, is someone about whom we know little, and our accounts of his intellectual attitudes are frustratingly meagre. His uncompromising attitude about our never having reason to commit ourselves to anything led to unfriendly jokes, such as that he had to be looked after by unsceptical friends to stop him walking off cliffs, and the like. But there is an alternative tradition to the effect that he lived a normal life, so it is most probable that, like later sceptics, he took it that even when we cannot commit ourselves to beliefs we can live by the way things appear to us.