Socrates (469–399 BC)

6. Weakness of will denied

In Plato’s Protagoras Socrates also denies the possibility of weakness of will – being ‘mastered’ by some desire so as to act voluntarily in a way one knows is wrong or bad (see also Xenophon, Memorabilia III 9.4, IV 5.6.) All voluntary wrongdoing or bad action is due to ignorance of how one ought to act and why, and to nothing else. This would be easy to understand if Socrates were using ‘knowing’ quite strictly, to refer to the elevated and demanding sort of knowledge described in §5 (sometimes called ‘Socratic knowledge’). Someone could know an action was wrong or bad, with full ‘Socratic knowledge’, only if they were not just thoroughly convinced, but had a deep, fully articulated understanding, being ready with explanations to fend off objections and apparent difficulties, and prepared to show precisely why it was so. That would mean that these ideas were seated so deeply in the mind as to be ineradicable and unwaveringly present. Accordingly, a person with ‘Socratic knowledge’ could not come to hold even momentarily that the action in question would be the thing to do, and so they could never do it voluntarily.

However, Plato’s Socrates goes further. He explains his denial of weak-willed action by saying that a person cannot voluntarily do actions which, in doing them, they even believe to be a wrong or bad thing to do (Protagoras 358c–e). He gives a much-discussed, elaborate argument to establish this stronger conclusion, starting from assumptions identifying that which is pleasant with that which is good (352a–357e). These assumptions, however, he attributes only to ordinary people, the ones who say they believe in the possibility of weak-willed action; he makes it clear to the careful reader, if not to Protagoras, that his own view is simply that pleasure is a good thing, not ‘the’ good (351c–e; see 354b–d). Although some scholars have thought otherwise, Socrates himself does not adopt a hedonist analysis of the good in the Protagoras or elsewhere either in Plato or Xenophon; indeed, he speaks elsewhere against hedonist views (see Hedonism). The fundamental principle underlying his argument – a principle he thinks ordinary people will accept – is that voluntary action is always ‘subjectively’ rational, in the sense that an agent who acts to achieve some particular sort of value always acts with the idea that what they are doing achieves more of that value than alternatives then thought by them to be available would achieve. If someone performs an overall bad action because of some (lesser) good they think they will get from it, they cannot do it while believing it is bad overall. That would mean they thought they could have got more good by refraining, and their action would violate the principle just stated. Instead, at the time they acted (despite what they may have thought before or after acting), they believed (wrongly and ignorantly) that the action would be good overall for them to do. Thus ignorance, and only ignorance, is responsible for voluntary error. Weakness of will – knowingly pursuing the worse outcome – is psychologically impossible: ‘No one does wrong willingly’.

The details of this argument may not represent explicit commitments of the historical Socrates. None the less, his denial of weakness of will, understood as presented in Plato’s Protagoras, was the centre of a protracted debate in later times. First Plato himself, in Republic IV, then Aristotle in Nicomachean Ethics VII, argued against Socrates’ conclusion, on the ground that he had overlooked the fact that human beings have other sources of motivation that can produce voluntary actions, besides their ideas about what is good or bad, or right or wrong to do. ‘Appetites’ and ‘spirited desires’ exist also, which can lead a person to act in fulfilment of them without having to adopt the idea, in their beliefs about what is best to do, that so acting would be a good thing (see Plato §14; Aristotle §20, 22–23). The Stoics, however, and especially Chrysippus, argued vigorously and ingeniously in defence of Socrates’ analysis and against the Platonic–Aristotelian assumption of alternative sources of motivation that produce voluntary action on their own (see Stoicism §19). In fact, during Hellenistic times it was the Socratic, ‘unitary’ psychology of action that carried the day; the Platonic–Aristotelian alternative, dominant in the ‘common sense’ and the philosophy of modern times, was a minority view. The issues Socrates raised about weakness of will continue to be debated today.