Full Idea
Moral feeling, conscience, love of one's neighbour, and respect for oneself (self-esteem). There is no obligation to have these, because they lie at the basis of morality, as subjective conditions of receptiveness to the concept of duty.
Gist of Idea
Duty is impossible without prior moral feeling, conscience, love and self-respect
Source
Immanuel Kant (Metaphysics of Morals II:Doctrine of Virtue [1797], 399 Intro XII)
Book Reference
Kant,Immanuel: 'The Metaphysics of Morals', ed/tr. Gregor,Mary [CUP 1991], p.200
A Reaction
A bit of a revelation, this one, because I thought the only precondition for Kantian morality was rationality. Turns out that he agrees with Aristotle (Idea 46) that you can't started in morality if your heart isn't in the right place.
Related Idea
Idea 46 We must take for granted that we should act according to right principle [Aristotle]