9. Principles and Nature of the Operations of Reason. -- The remote principle of the operations of reason is the human substance composed of body and soul; the proximate, or immediate, principle is the intellectual faculty.{1}
Psychology teaches us that every act has its origin in the senses. While the material thing, which is the object of our sensations, is always determinate, made of particular matter, endowed with particular properties, the object of the concept is abstract and universal, that is to say, is considered apart from the particular attributes which really belong to it in nature (abstrahere, to consider separately), and it thereby becomes universal, or applicable to an indefinite number of individual subjects. This bell, which I see and touch, is made of bronze, it is round in shape, it gives a pleasant sound, it is there on my desk at this moment as I look at it. All this is determinate. Now I am able to think of a bell which abstracts from all these peculiarities, and which will serve to represent to me, at least imperfectly, all bells of whatsoever material they may be made, whatsoever may be their peculiarities of shape or of tone, whatsoever the position in space or the moment of time in which they may exist.
{1} See Psychology, no. 153.