Western philosophical scepticism begins with the Greeks, soon settles down in the Hellenistic world into two main forms, the Academic and the Pyrrhonian. As I noted before, the latter is the one for which I feel the most sympathy, the one most inclined towards undermining ‘the disease called Dogmatism’ – the enemy of true sceptics everywhere. Its virtue lies in its very lack of claims; in its desire to be a technique for analysing the claims of others, and identifying their shortcomings, rather than a new source of authority in its own right (a condition that Academic scepticism tended to gravitate towards). While classical Pyrrhonians wished to reach a condition of quietude, I am more concerned to use scepticism to create disquiet, not just amongst dogmatists, but within the sceptical community itself. Our own position should be under constant review, and should never become too comfortable. Nevertheless, I think we can reasonably appropriate elements of Pyrrhonism into the current project. As the noted scholar on the classical Pyrrhonian tradition, Jonathan Barnes, has argued, its ‘forms and structures remain today among the central issues in the theory of knowledge; . . . they still provide the subject of epistemology with some of its most cunning puzzles and most obdurate problems’.5 Pyrrhonism is to be considered, therefore, more than just a historical curiosity. It provides an extremely useful point of reference for rethinking the project of scepticism in the twenty-first century. This is particularly so since, as Julia Annas and Jonathan Barnes point out, Pyrrhonism’s emphasis was very firmly on belief: ‘The ancient sceptics did not attack knowledge: they attacked belief’ (whereas in modern scepticism it is often the opposite).6 As it is precisely belief that we are concerned to call into question too, it is appropriate for us to link up as much as we can with the classical sceptical tradition.

Pyrrhonism can be traced back to Pyrrho of Elis (c. 360–275 BC), and his disciple Timon (c. 315–225 BC), but was only subsequently developed as a proper theory of scepticism by Aenesidemus (c. 100–40 BC). Sextus Empiricus owes his key position in the history of scepticism to being the author of the only surviving texts from the Pyrrhonian tradition, Outlines of Scepticism and Against the Mathematicians, rather than to any originality of interpretation of his own (one theory is that he owes a considerable debt to an obscure figure from the previous century called Agrippa7). The theories of his forebears are channelled through these works by Sextus, which provide us with an extensive body of arguments – arranged into ten ‘modes’, such as ‘disagreement’, ‘infinite regress’, and ‘reciprocity’ (circular reasoning8) – as to why we should desist from making judgements on matters of knowledge. In every case these modes prevent clear-cut decisions being made about disputed issues.

For Sextus, Scepticism is an ability to set out oppositions among things which appear and are thought of in any way at all, an ability by which, because of the equipollence in the opposed objects and accounts, we come first to a suspension of judgement and afterwards to tranquillity. . . . The chief constitutive principle of scepticism is the claim that to every account an equal account is opposed; for it is from this, we think, that we come to hold no belief. (‘Equipollence’ means for Sextus, ‘equality with regard to being convincing or unconvincing’.) Scepticism is presented in the Outlines as a ‘mental attitude’ (much as postmodernism has been defined by some commentators in our own day), ‘a purge that eliminates everything including itself’. Sextus himself emphasises the social utility of the sceptical project, arguing that ‘[s]ceptics are philanthropic and wish to cure by argument, as far as they can, the conceit and rashness of the Dogmatists’, clearly signalling his belief that the world would be a much better place were scepticism to become the dominant outlook. After the Hellenistic period, however, the Pyrrhonian tradition largely disappears for several centuries, with philosophy in the West increasingly being drawn into the web of Christian theology and made to serve its more specialised interests (enquiries into the nature of God and his properties, proofs for the existence of God, concerns of that nature).

In Richard H. Popkin’s summation, the Pyrrhonist sceptic ‘lives undogmatically, following his natural inclinations, the appearances he is aware of, and the laws and customs of his society, without ever committing himself to any judgment about them’. I find this an attractive character portrait, particularly when coupled with the Pyrrhonist’s focus on belief; but I would like to build a few more elements into it, such as a more robust attitude towards dogmatism and a desire to see it challenged whenever it raises its head, as it almost always will, in institutional authority. Pyrrhonism can sound a bit passive and interior to the discipline of philosophy: I would like it to be more active and outward looking, an encouragement to making links and establishing common cause with the like-minded rather than a retreat into the personal. That way we can begin to see how we can develop a scepticism for our own times, politically engaged and directed against abuses of power rather than trying to be clever for its own sake (as so much of negatively inclined philosophy can be, especially when it is denying the grounds for knowledge). As far as I am concerned, that is the acceptable face of relativism.

Not everyone finds the Pyrrhonian ideal desirable. One recent robust attack has come from R. J. Hankinson, who wonders whether following its prescriptions really will lead to a more contented existence for all as Sextus claims: ‘perhaps some people need a good hearty dose of naive Dogmatism (as religion apparently comforts the bereaved)’.14 Hankinson argues that Pyrrhonian-style scepticism will only have a therapeutic value for those of a particular temperament and that it will have nothing to say to others. But that is to concentrate on its psychological impact rather than its philosophical and ideological implications. I have no wish to mock the beliefs of the bereaved, for whom religion may well provide a source of solace at a very trying time (and most of us have seen it do just that with relatives or friends at one time or other), but religion is about more than helping the emotionally distraught. It goes well beyond that laudable enough aim to build-up empires that inevitably seem to gravitate towards repression of other viewpoints. Neither is dogmatism just a personal matter; invariably it becomes a group dynamic, and in that form it turns into something much more sinister whose will is hard to counter. But as I said above, it is my intention to build on the Pyrrhonian base so that it achieves a political dimension; hopefully, that will deflect the criticisms of such as Hankinson to scepticism’s shortcomings.