There is no sin unless through a man's own will, and hence the reward when we do right things also of our own will."

(Against Fortunatus)

Sin is looking for the right thing in the wrong place.

I inquired what wickedness is, and I didn't find a substance, but a perversity of will twisted away from the highest substance – You oh God – towards inferior things, rejecting its own inner life and swelling with external matter.

He that becomes protector of sin shall surely become its prisoner.

Though I was retreating from the Truth, I appeared to myself to be going toward it because I did not yet know that evil with nothing but the privation of good.

There can only be two basic loves... the love of God unto the forgetfulness of self, or the love of self unto the forgetfulness and denial of God.