Metaphysics Of Ethics

When it is said of the perfection that belongs to man generally (properly speaking, to humanity), that it is in itself a duty to make this our end, it must be placed in that which may be the effect of one`s deed, not in that which is merely an endowment for which we have to thank nature; for otherwise it would not be duty. Consequently, it can be nothing else than the cultivation of one`s power (or natural capacity) and also of one`s will (moral disposition) to satisfy the requirement of duty in general.