Weakness of will
Weakness of will, which philosophers often call by its ancient Greek name akrasia, describes actions that one takes even while personally believing, or knowing, them to be wrong. The classic puzzle about weakness of will--which remains a puzzle for philosophers to this day--is whether it is possible really to know that an action is wrong and yet commit it. In the Meno and other dialogues by Plato, Socrates claims that it is not, and so that acting contrary to virtue is a sign of ignorance. Plato himself rejected this view, arguing that desires can sometimes overwhelm the intellectual recognition of what is right. Most contemporary philosophers follow him, claiming that we can knowingly be "tempted" by illicit pleasures, or to avoid virtues that cause pain.