Ethics, or Know Yourself (Scito te ipsum)

A short treatise on ethics, written in the late 1130s, whose title means 'know yourself'. Abelard separates four things that ordinary talk runs together: vice, a disposition of the mind that inclines us to sin; the will or desire; the outward deed; and sin itself. Sin, he argues, lies only in consenting to what we believe we should not do, which amounts to contempt for God. Desire is not sin, since we can want something and refuse to consent, and the deed adds nothing to guilt or merit, since the same act can be done well or badly. He tests the view on hard cases, such as a servant who kills his master to save his own life, and those who persecuted Christ or the martyrs believing they served God, whom he does not count as sinning in the strict sense. The text then discusses repentance, confession and satisfaction, and a second book breaks off after a few pages.

It is the boldest medieval case that moral worth lies in intention rather than in action, and its arguments about consent and blame still bear on debates about responsibility.