The analysis thus far he claims to be strictly scientific; he now proceeds to vary the case, taking actions of our own.  I am supposed entrusted by a dying friend with a deposit for another, and a struggle ensues between interest and probity as to whether I should pay it.  If interest conquers, remorse ensues.  He paints the state of remorse, and analyzes it into the same elements as before, the idea of good and evil, of an obligatory law, of liberty, of merit and demerit; it thus includes the whole phenomenon of morality.  The exactly opposite state that follows upon the victory of probity, is proved to imply the same facts.

The Moral Sentiment, so striking in its character, has by some been supposed the foundation of all morality, but in point of fact it is itself constituted by these various judgments.  Now that they are known to stand as its elements, he goes on to subject each to a stricter analysis, taking first the judgment of good and evil, which is at the bottom of all the rest.  It lies in the original constitution of human nature, being simple and indecomposable, like the judgment of the True and the Beautiful.  It is absolute, and cannot be withheld in presence of certain acts; but it only declares, and does not constitute, good and evil, these being real and independent qualities of actions.  Applied at first to special cases, the judgment of good gives birth to general principles that become rules for judging other actions.  Like other sciences, morality has its axioms, justly called moral truths; if it is good to keep an oath, it is also true, the oath being made with no other purpose than to be kept.  Faithful guarding as much belongs to the idea of a deposit, as the equality between its three angles and two right angles to the idea of a triangle.  By no caprice or effort of will can a moral verity be made in the smallest degree other than it is.

But, he goes on, a moral verity is not simply to be believed; it must also be practised, and this is obligation, the second of the elements of moral sentiment.  Obligation, like moral truth, on which it rests, is absolute, immutable, universal.  Kant even went so far as to make it the principle of our morality; but this was subjectivizing good, as he had subjectivized truth.  Before there is an obligation to act, there must be an intrinsic goodness in the action; the real first truth of morality is justics, i.e., the essential distinction of good and evil.  It is justice, therefore, and not duty, that strictly deserves the name of a principle.