In fact, if you read what Kant has to say about feeling, desire and emotion, you see that he is not at all hostile to these. He is suspicious of them insofar as they represent the corruption of social life (here he follows Rousseau), but he also thinks a variety of feelings (including respect and love of humanity) arise directly from reason - there is, in other words, no daylight between the heart and the head regarding such feelings.
Allen W. WoodNotice that tearing oneself out of the insensible state is the opposite of remaining in it; the man who is beneficent from duty nevertheless acts with feelings, if not with empirical inclinations.
Allen W. WoodIt is a culturally interesting (but also deeply depressing) fact that many religious claims seem to retain their emotional power for believers only if taken in ways that are intellectually unsupportable and even morally contemptible.
Allen W. WoodIt was an important part of Mendelssohn's philosophical and religious view that the traditional rationalist proofs for God's existence should be sound an convincing. Kant thought they were not. So Kant's critique was world-shaking for Mendelssohn.
Allen W. Wood