Whether the devil is directly the cause of man's sinning?

❌ Objection 1 : It would seem that the devil is directly the cause of man's sinning. For sin consists directly in an act of the appetite. Now Augustine says (De Trin. iv, 12) that "the devil inspires his friends with evil desires"; and Bede, commenting on Acts 5:3, says that the devil "draws the mind to evil desires"; and Isidore says (De Summo Bono ii, 41; iii, 5) that the devil "fills men's hearts with secret lusts." Therefore the devil is directly the cause of sin.

❌ Objection 2 : Further, Jerome says (Contra Jovin. ii, 2) that "as God is the perfecter of good, so is the devil the perfecter of evil." But God is directly the cause of our good. Therefore the devil is directly the cause of our sins.

❌ Objection 3 : Further, the Philosopher says in a chapter of the Eudemein Ethics (vii, 18): "There must needs be some extrinsic principle of human counsel." Now human counsel is not only about good things but also about evil things. Therefore, as God moves man to take good counsel, and so is the cause of good, so the devil moves him to take evil counsel, and consequently is directly the cause of sin.