332. Forms of use for perfecting the rational faculty are all disciplines which provide instruction in those matters just mentioned, and which are called sciences and fields of study. These relate to natural, economic, civil, and moral concerns, and they are learned either from parents and teachers, or from books, or from dealings with others, or on one's own through reflections on such concerns. These disciplines perfect the rational faculty to the extent that they are forms of use in a higher degree, and they remain to the extent that they are applied to life. We do not have the space to enumerate these forms of use, both because of their multitude, and because of their varying relation to the common good.