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 reason which, in every case of law, holds before a man his
duty for acquittal or condemnation; consequently it does not refer
to an object, but only to the subject (affecting the moral feeling
by its own act); so that it is an inevitable fact, not an obligation
and duty. When, therefore, it is said, "This man has no conscience,"
what is meant is that he pays no heed to its dictates. For if he
really had none, he would not take credit to himself for anything done
according to duty, nor reproach himself with violation of duty, and
therefore he would be unable even to conceive the duty of having a
conscience.
{INTRODUCTION ^paragraph 145}
I pass by the manifold subdivisions of conscience, and only
observe what follows from what has just been said, namely, that
there is no such thing as an erring conscience. No doubt it is
possible sometimes to err in the objective judgement whether something
is a duty or not; but I cannot err in the subjective whether I have
compared it with my practical (here judicially acting) reason for
the purpose of that judgement: for if I erred I would not have
exercised practical judgement at all, and in that case there is
neither truth nor error. Unconscientiousness is not want of
conscience, but the propensity not to heed its judgement. But when a
man is conscious of having acted according to his conscience, then, as
far as regards guilt or innocence, nothing more can be required of
him, only he is bound to enlighten his understanding as to what is
duty or not; but when it comes or has come to action, then
conscience speaks involuntarily and inevitably. To act conscientiously
can, therefore, not be a duty, since otherwise it would be necessary
to have a second conscience, in order to be conscious of the act of
the first.
The duty here is only to cultivate our conscience, to quicken
our attention to the voice of the internal judge, and to use all means
to secure obedience to it, and is thus our indirect duty.