Yes. Ordinary Jo is exactly the target of Socrates’ argument – except that he calls them ‘the many’, or ‘most people’. Here’s what they think, according to Socrates:
He then develops at some length an argument against this view of Ordinary Jo’s that the argument is to the effect that for most people – Ordinary Jo in person, in fact – their only motivation is pleasure and the avoidance of pain. So all their values and wants become commensurable, and we can treat ‘pleasant’ and ‘good’ (or ‘painful’ and ‘bad’) as interchangeable. What Socrates ends up with is close, in effect, to the view that wanting something to be done is a bit like thinking it’s right, and wanting something not to be done is a bit like thinking it’s wrong. This leads to something which Socrates presents as absurd:
Well, if the person asking us happens to be a bit aggressive, they’ll say, ‘What you’re saying is ridiculous – that someone does what’s bad, knowing it’s bad, even though he doesn’t have to, because he’s been overcome by what’s good!’’
The problem here seems to be that the akratic (the person lacking in self-control) is taken to have blatantly self-contradictory views, and that’s taken to be absurd. So it seems as if Socrates is continuing to assume that the same person can’t possibly have competing desires or contradictory beliefs at the same time. That is, Socrates is still apparently agreeing with Ordinary Jo that if knowing what’s right and wrong were not a different kind of state from the wanting or desiring which actually affects your action, akrasia wouldn’t be possible. He differs from Ordinary Jo only in holding this:
Most commentators seem to think so. The focus is the argument in Republic IV (roughly 435e-441c), where Socrates argues that there are different parts of the soul, on the grounds that there are clearly occasions when the soul is in conflict with itself – something which is held to be intelligible only as involving different parts of the soul being in conflict with each other. The key moment is a place where most commentators take Socrates to be rejecting the view which is argued for in the Protagoras that wanting something to be done is a bit like thinking it’s right, and wanting something not to be done is a bit like thinking it’s wrong. In particular, most commentators take Socrates in the Republic to argue for at least a restricted version of one of Ordinary Jo’s views that at least for certain kinds of want, wanting something to be done is unlike thinking it’s right, and wanting something not to be done is unlike thinking it’s wrong. The key passage is this place at 437d-e, where Socrates introduces the idea of ‘thirst itself’:
Most commentators take Socrates here to be introducing the idea of a specially basic kind of desire, which is neither rational nor irrational – which is, rather, non-rational, and therefore something wholly unlike a thought that something is good or bad, right or wrong. They think of it as a kind of brute, animal desire, almost just physiological. And these commentators take Socrates to be explicitly insisting that this kind of want is unlike any kind of value judgement – a judgement that something is good or right – in this passage which comes a moment later:
Well, then [I said], let no one catch us when we’re not looking and undermine us by saying that nobody wants drink, but only a good drink, or food, but only good food, on the grounds that everyone wants what’s good. This would mean that if thirst is an appetite or want, it will be an appetite for a good drink, or a good whatever it’s an appetite for – and similarly for the other appetites.