To Florus 5.27

You therefore ask where this evil comes from which rightly deserves the name evil: sin. I reply that it is exceedingly unskilled to ask the origin of something whose definition has not yet been established. Let us first see whether it exists, then what it is, and last where it comes from. I did this in the first book of the present work, but there I proceeded with some points already secure. Let us now question whether evil exists.