Chapter 114 — What is understood in things by the name good or bad

Here we must consider that, as the term ‘good’ signifies perfect being, so the term ‘evil’ signifies nothing else than privation of perfect being. For privation is properly taken as of that which is made to be possessed, and at a certain time in a certain way. Evidently, therefore, a thing is called ‘evil’ if it lacks a perfection it ought to have. Thus if a man lacks the sense of sight, this is an evil for him. But the same lack is not an evil for a stone, for the stone is not by nature such as to have the faculty of sight.