What are the Ends which are also Duties?

They are: A. OUR OWN PERFECTION, B. HAPPINESS OF OTHERS.

We cannot invert these and make on one side our own happiness, and on the other the perfection of others, ends which should be in themselves duties for the same person. For one's own happiness is, no doubt, an end that all men have (by virtue of the impulse of their nature), but this end cannot without contradiction be regarded as a duty. What a man of himself inevitably wills does not come under the notion of duty, for this is a constraint to an end reluctantly adopted. It is, therefore, a contradiction to say that a man is in duty bound to advance his own happiness with all his power.

It is likewise a contradiction to make the perfection of another my end,