Akrasia is lack of self-control or weakness of will.
It’s normally understood to involve one or other of these two things:
So for an example of 2 here, think of someone who knows it’s wrong for them to have another drink, because they’ve promised they wouldn’t, but can’t resist getting one anyway. Most people think it’s obvious that akrasia is possible—indeed, most of us think we’re all akratic (weak-willed) quite a lot of the time. We probably don’t normally think there could really be a philosophical problem about akrasia.
This means that Ordinary Jo must have a certain view, not only about akrasia, but about the nature of morality and the nature of desire.
It looks as if Ordinary Jo thinks your knowledge of what’s right and wrong is just overwhelmed by your desire (or disinclination) – as if by some powerful force.
This is a problem for Ordinary Jo, how can he explain what’s irrational about akrasia? Obviously, it’s best to do what’s right, and not do what’s wrong – but what’s specially bad about not doing what you know is right, or doing what you know is wrong?
Click here to follow one solution to Ordinary Jo’s problem