Full Idea
Moral self-knowledge, which seeks to penetrate into the depths (the abyss) of one's heart that are quite difficult to fathom, is the beginning of all human wisdom.
Gist of Idea
Moral self-knowledge is the beginning of all human wisdom
Source
Immanuel Kant (Metaphysics of Morals II:Doctrine of Virtue [1797], 441 I.I)
Book Reference
Kant,Immanuel: 'The Metaphysics of Morals', ed/tr. Gregor,Mary [CUP 1991], p.236
A Reaction
I'm not clear what I am supposed to be looking for on this quest. I'm guessing that being completely honest about one's own maxims in moral action would be a good start. And maybe confronting one's murkier desires.
Related Idea
Idea 519 One must avoid even speaking of evil deeds [Democritus (attr)]