(3) Whether good is the subject of evil?
(4) Whether evil totally corrupts good?
(5) The division of evil into pain and fault.
(6) Whether pain, or fault, has more the nature of evil? _______________________
FIRST ARTICLE [I, Q. 48, Art. 1]
Whether Evil Is a Nature?
Objection 1: It would seem that evil is a nature. For every genus is a nature. But evil is a genus; for the Philosopher says (Praedic. x) that "good and evil are not in a genus, but are genera of other things." Therefore evil is a nature.
Obj. 2: Further, every difference which constitutes a species is a nature. But evil is a difference constituting a species of morality; for a bad habit differs in species from a good habit, as liberality from illiberality. Therefore evil signifies a nature.
Obj. 3: Further, each extreme of two contraries is a nature. But evil and good are not opposed as privation and habit, but as contraries, as the Philosopher shows (Praedic. x) by the fact that between good and evil there is a medium, and from evil there can be a return to good. Therefore evil signifies a nature.
Obj. 4: Further, what is not, acts not. But evil acts, for it corrupts good. Therefore evil is a being and a nature.