Akrasia, occasionally transliterated as acrasia, is the state of acting against one’s better judgement.
The problem goes back at least as far as Plato. Socrates, in Plato’s Protagoras, asks precisely how this is possible:
“If one judges action A to be the best course of action, why would one do anything other than A?”
In the dialogue Protagoras, Socrates attests that akrasia is an illogical moral concept, claiming “No one goes willingly toward the bad” (358d). If a person examines a situation and decides to act in the way he determines to be best, he will actively pursue this action, as the best course is also the good course, i.e. man’s natural goal.
An all-things-considered assessment of the situation will bring full knowledge of a decision’s outcome and worth linked to well-developed principles of the good.
A person, according to Socrates, never chooses to act poorly or against his better judgement; actions that go against what is best are only a product of being ignorant of facts or knowledge of what is best or good.
On a Biblical note, in Matthew 23:25 Jesus uses it to describe hypocritical religious leaders. The Apostle Paul also gives akrasia as a reason for a husband and wife to not deprive each other of sex (I Corinthians 7:5).