Socrates insisted nobody knowingly chooses the worse option. Your phone disagrees.
You know you should study, and you scroll instead. Greek philosophers called this akrasia, acting against your own better judgment. Socrates argued it cannot really happen, since knowing the good means doing it. For two and a half thousand years, thinkers have tried to square that claim with ordinary experience.
Akrasia is often translated as weakness of will or incontinence. The puzzle it poses is sharp: if reason judges one action best, what makes someone deliberately do another? In Plato's Protagoras, Socrates takes the bold line that no one willingly goes towards what they believe is bad. Virtue is knowledge, and people pursue what they take to be good. Apparent weakness must therefore be ignorance, a miscalculation of consequences or a shaky grasp of what is truly beneficial. The cost of that tidy view is that it clashes with everyday life.
Aristotle, devoting Book VII of the Nicomachean Ethics to the problem, took experience seriously. He located the failure in opinion rather than raw desire and described two kinds. The weak person deliberates, reaches the right answer, then gives in to feeling. The impetuous person never deliberates at all, acts on emotion and feels regret only afterwards. Its opposite, enkrateia, is mastery over one's desires, and Aristotle did not count akrasia as a vice, because it is a failure to act on knowledge rather than a bad choice. Augustine later moved the problem from knowledge to the will.
Modern philosophers have kept refining it. Donald Davidson framed three claims that seem jointly impossible: we want most what we judge best, we do what we want most, and yet sometimes we act against our best judgment. His answer was that the akratic person judges using only some of the relevant considerations, never reaching an all-things-considered verdict. Amélie Rorty split akrasia into four types, matched to stages of reasoning from setting goals to forming character.
Psychology offers a mechanism. George Ainslie links akrasia to hyperbolic discounting, the tendency for judgments to shift as a reward draws near, so the tempting option looks different up close.
Source: Akrasia
