Augustus Hopkins Strong made an analogy between conscience and faith in his Systematic Theology:
As already intimated, conscience is not a separate faculty, like intellect, sensibility, and will, but rather a mode in which these faculties act. Like consciousness, conscience is an accompanying knowledge. Conscience is a knowing of self (including our acts and states) in connection with a moral standard, or law. Adding now the element of feeling, we may say that conscience is man’s consciousness of his own moral relations, together with a peculiar feeling in view of them. It thus involves the combined action of the intellect and of the sensibility, and that in view of a certain class of objects, vix.: right and wrong.
There is no separate ethical faculty any more than there is a separate aesthetic faculty. Conscience is like taste: it has to do with moral being and relations, as taste has to do with aesthetic being and relations. But the ethical judgment and impulse are, like the aesthetic judgment and impulse, the mode in which the intellect, sensibility and will act with reference to a certain class of objects. Conscience deals with the right, as taste deals with the beautiful. As consciousness (con and scio) is a con-knowing, a knowing of our thoughts, desires and volitions in connection with a knowing of the self that has these thoughts, desires and volitions; so conscience is a con-knowing, a standard or law which is conceived of as our true self, and therefore as having authority over us. Ladd, Philosophy of the Mind, 183-85– ‘The condemnation of self involves self-diremption, double consciousness. Without it Kant’s categorical imperative is impossible. The one self lays down the law to the other self, judges it, threatens it. This is what is meant, when the apostle says: ‘It is no more I that do it, but sin that dwelleth in me’ (Rom. 7:17).”*
*Systematic Theology: A Compendium Designed for the Use of Theological Students (Westwood, NJ: Fleming H. Revell Company, 1907), 498.