332. Uses for perfecting the rational are all the things which teach the subjects already mentioned, and are called knowledges and studies pertaining to natural, economic, civil and moral affairs. These are acquired from parents and teachers, or from books, or from associations with others, or by reflection on these subjects by oneself. These things perfect the rational so far as they are uses in a higher degree and they endure so far as they are applied to life. Space forbids enumeration of these uses, both on account of their abundance, and of their varied relation to the common good.