Objection 1. It would seem that a thing cannot be an object of universal hatred. Because hatred is a passion of the sensitive appetite, which is moved by an apprehension in the senses. But the senses cannot apprehend the universal. Therefore a thing cannot be an object of universal hatred.
Objection 2. Further, hatred is caused by disagreement; and where there is disagreement, there is nothing in common. But the notion of universality implies something in common. Therefore nothing can be the object of universal hatred.
Objection 3. Further, the object of hatred is evil. But "evil is in things, and not in the mind" (Metaph. vi, 4). Since therefore the universal is in the mind only, which abstracts the universal from the particular, it would seem that hatred cannot have a universal object.
On the contrary, The Philosopher says (Rhet. ii, 4) that "anger is directed to something singular, whereas hatred is also directed to a thing in general; for everybody hates the thief and the backbiter."
I answer that, There are two ways of speaking of the universal: first, as considered under the aspect of universality; secondly, as considered in the nature to which it is ascribed: for it is one thing to consider the universal man, and another to consider a man as man. If, therefore, we take the universal, in the first way, no sensitive power, whether of apprehension or of appetite, can attain the universal: because the universal is obtained by abstraction from individual matter, on which every sensitive power is based.
Nevertheless the sensitive powers, both of apprehension and of appetite, can tend to something universally. Thus we say that the object of sight is color considered generically; not that the sight is cognizant of universal color, but because the fact that color is cognizant by the sight, is attributed to color, not as being this particular color, but simply because it is color. Accordingly hatred in the sensitive faculty can regard something universally: because this thing, by reason of its common nature, and not merely as an individual, is hostile to the animal--for instance, a wolf in regard to a sheep. Hence a sheep hates the wolf universally. On the other hand, anger is always caused by something in particular: because it is caused by some action of the one that hurts us; and actions proceed from individuals. For this reason the Philosopher says (Rhet. ii, 4) that "anger is always directed to something singular, whereas hatred can be directed to a thing in general."
But according as hatred is in the intellectual part, since it arises from the universal apprehension of the intellect, it can regard the universal in both ways.
Reply to Objection 1. The senses do not apprehend the universal, as such: but they apprehend something to which the character of universality is given by abstraction.
Reply to Objection 2. That which is common to all cannot be a reason of hatred. But nothing hinders a thing from being common to many, and at variance with others, so as to be hateful to them.
Reply to Objection 3. This argument considers the universal under the aspect of universality: and thus it does not come under the sensitive apprehension or appetite.
Source: Summa Theologica (New Advent)