Between the ability to know and the ability to desire lies the ability to feel, by means of which we feel pleasure or displeasure in some subject matter, approve of it, deem it good, and find it pleasant or disapprove of it, find fault with it, and find it unpleasant. There are thoughts and representations in which we take no part and which are not connected with any sentiments. There are also sentiments that do not pass over into desires. We can find a piece of music, a painting beautiful and be moved by it without desiring anything.

The goal of the ability to know is the true. That is, insofar as we possess a ability to know, we strive to make the concepts in our soul agree with the properties of their objects.

The goal of the ability to feel is the good. That is, insofar as we possess an ability to feel, we strive to make the objective properties agree with our concepts of goodness, order, and beauty. This object is occasionally in us ourselves if we endeavor to alter our thoughts and sentiments themselves in keeping with the rule of goodness, beauty, and so forth.

Thus, within the human being, there are apparently contrasting inclinations to truth and to fiction: to truth as soon as the ability to know is supposed to be engaged, to fiction, on the other hand, as soon as we intend merely to sustain our ability to feel.