The Metaphysical Elements of Ethics by Immanuel Kant Chapter 12 Page 4

vital force could no longer produce any effect on this feeling, then his humanity would be dissolved (as it were by chemical laws) into mere animality and be irrevocably confounded with the mass of other physical beings. But we have no special sense for (moral) good and evil any more than for truth, although such expressions are often used; but we have a susceptibility of the free elective will for being moved by pure practical reason and its law; and it is this that we call the moral feeling.

B. OF CONSCIENCE

Similarly, conscience is not a thing to be acquired, and it is not a duty to acquire it; but every man, as a moral being, has it originally within him. To be bound to have a conscience would be as much as to say to be under a duty to recognize duties. For conscience is practical