The primary _officium_ (in a larger sense than our word Duty) of man is (they said) to keep himself in the state of nature; the second or derivative _officium_ is to keep to such things as are _according to nature_, and to avert those that are _contrary to nature_; our gradually increasing experience enabled us to discriminate the two. The youth learns, as he grows up, to value bodily accomplishments, mental cognitions and judgments, good conduct towards those around him,--as powerful aids towards keeping up the state of nature. When his experience is so far enlarged as to make him aware of the order and harmony of nature and human society, and to impress upon him the comprehension of this great _ideal_, his emotions as well as his reason become absorbed by it. He recognizes this as the only true Bonum or Honestum, to which all other desirable things are referable,--as the only thing desirable for itself and in its own nature. He drops or dismisses all those _prima naturae_ that he had begun by desiring. He no longer considers any of them as worthy of being desired in itself, or for its own sake. While therefore (according to Peripatetics as well as Stoics) the love of self and of preserving one's own vitality and activity, is the primary element, intuitive and connate, to which all rational preference (_officium_) was at first referred,--they thought it not the less true, that in process of time, by experience, association, and reflection, there grows up in the mind a grand acquired sentiment or notion, a new and later light, which extinguishes and puts out of sight the early beginning. It was important to distinguish the feeble and obscure elements from the powerful and brilliant aftergrowth; which indeed was fully realized only in chosen minds, and in them, hardly before old age. This idea, when once formed in the mind, was _The Good_--the only thing worthy of desire for its own sake. The Stoics called it the only Good, being sufficient in itself for happiness; other things being not good, nor necessary to happiness, but simply preferable or advantageous when they could be had: the Peripatetics recognized it as the first and greatest good, but said also that it was not sufficient in itself; there were two other inferior varieties of good, of which something must be had as complementary (what the Stoics called _praeposita_ or _sumenda_). Thus the Stoics said, about the origin of the Idea of Bonum or Honestum, much the same as what Aristotle says about ethical virtue. It is not implanted in us by nature; but we have at birth certain initial tendencies and capacities, which, if aided by association and training, enable us (and that not in all cases) to acquire it.