Part 1810

natural appetite, owing to one and the same thing being naturally suitable to one thing, and naturally unsuitable to another: thus heat is becoming to fire and unbecoming to water: and in respect of the animal appetite, owing to one and the same thing being apprehended by one as good, by another as bad.

* Objection 1: * It would seem that love is not a cause of hatred. For "the opposite members of a division are naturally simultaneous" (Praedic. x). But love and hatred are opposite members of a division, since they are contrary to one another. Therefore they are naturally simultaneous. Therefore love is not the cause of hatred.

* Objection 2: * Further, of two contraries, one is not the cause of the other. But love and hatred are contraries. Therefore love is not the cause of hatred.

* Objection 3: * Further, that which follows is not the cause of that which precedes. But hatred precedes love, seemingly: since hatred implies a turning away from evil, whereas love implies a turning towards good. Therefore love is not the cause of hatred.

* On the contrary, * Augustine says (De Civ. Dei xiv, 7,9) that all emotions are caused by love. Therefore hatred also, since it is an emotion of the soul, is caused by love.

* I answer that, * As stated above (A[1]), love consists in a certain agreement of the lover with the object loved, while hatred consists in a certain disagreement or dissonance. Now we should consider in each thing, what agrees with it, before that which disagrees: since a thing disagrees with another, through destroying or hindering that which agrees with it. Consequently love must needs precede hatred; and nothing is hated, save through being contrary to a suitable thing which is loved. And hence it is that every hatred is caused by love.

* Reply to Objection 1: * The opposite members of a division are sometimes naturally simultaneous, both really and logically; e.g. two species of animal, or two spec