Objection 2: Further, "All men have a natural desire for knowledge," as stated in the beginning of the Metaphysics i, 1. But knowledge is only of truth. Therefore truth is naturally desired and loved. But that which is in a thing naturally, is always in it. Therefore no man can hate the truth.
Objection 3: Further, the Philosopher says (Rhet. ii, 4) that "men love those who are straightforward." But there can be no other motive for this save truth. Therefore man loves the truth naturally. Therefore he cannot hate it.
On the contrary, The Apostle says (Gal.4:16): "Am I become your enemy because I tell you the truth?" [*St. Thomas quotes the passage, probably from memory, as though it were an assertion: "I am become," etc.]
I answer that, Good, true and being are the same in reality, but differ as considered by reason. For good is considered in the light of something desirable, while being and true are not so considered: because good is "what all things seek." Wherefore good, as such, cannot be the object of hatred, neither in general nor in particular. Being and truth in general cannot be the object of hatred: because disagreement is the cause of hatred, and agreement is the cause of love; while being and truth are common to all things. But nothing hinders some particular being or some particular truth being an object of hatred, in so far as it is considered as hurtful and repugnant; since hurtfulness and repugnance are not incompatible with the notion of being and truth, as they are with the notion of good.
Now it may happen in three ways that some particular truth is repugnant or hurtful to the good we love. First, according as truth is in things as in its cause and origin. And thus man sometimes hates a particular truth, when he wishes that what is true were not true. Secondly, according as truth is in man's knowledge, which hinders him from gaining the object loved: such is the case of those who wish not to know the truth of faith, that they may sin freely; in whose person it is said (Job 21:14): "We desire not the knowledge of Thy ways." Thirdly, a particular truth is hated, as being repugnant, inasmuch as it is in the intellect of another man: as, for instance, when a man wishes to remain hidden in his sin, he hates that anyone should know the truth about his sin. In this respect, Augustine says (Confess. x, 23) that men "love truth when it enlightens, they hate it when it reproves." This suffices for the Reply to the First Objection.
Reply to Objection 2: The knowledge of truth is lovable in itself: hence Augustine says that men love it when it enlightens. But accidentally, the knowledge of truth may become hateful, in so far as it hinders one from accomplishing one's desire.
Reply to Objection 3: The reason why we love those who are straightforward is that they make known the truth, and the knowledge of the truth, considered in itself, is a desirable thing.