Specific Character.—The form of mental activity which is characteristic of this faculty, is the perception of relations, that which Dr. Brown calls relative suggestion, but which we should prefer to term relative conception. The mind is so constituted that when distinct objects of thought are presented, it conceives at once the notion of certain relations existing between those objects. One is larger, one smaller, one is here, the other there, one is a part in relation to a whole, some are like, others unlike each other. The several relations that may exist and fall under the notice of this power of the mind are too many to be easily enumerated. The more important are, position, resemblance, proportion, degree, comprehension. All these may, perhaps, by a sufficiently minute analysis, be resolved into one—that of comprehension, or the relation of a whole to its parts.
Comprehensive of several Processes.—The faculty now under consideration will, on careful investigation, be found to underlie and comprehend several mental processes usually ranked as distinct operations and faculties of the mind, but which are at most only so many forms of the general power of relative conception. Such are the mental operations usually known as judgment, abstraction, generalization, and reasoning. Of these, and their relation to the general faculty comprehensive of all, we shall have occasion to speak further as we proceed.
Two Modes of Operation.—As the relations of object to object may all be comprised under the general category of comprehension, or the whole and its parts, there are manifestly two modes or processes in which the reflective faculty may put forth its activity. It may combine the several parts or elements to form a complex whole, or it may divide the complex whole into its several parts and elements. In the one case, it works from the parts, as already resolved, to the whole; in the other, from the whole, as already combined, to the parts. The one is the compositive or synthetic, the other, the analytic or divisive process. Each will claim our attention.
CHAPTER I.
THE SYNTHETIC PROCESS—GENERALIZATION.
§ I.—Nature of the Synthetic Process.
Our Conceptions often Complex.—If we examine attentively the various notions or conceptions of the mind, we find that a large part of them are in a sense complex—comprising, in a word, a certain aggregate of properties, which, taken together, constitute our conception of the object. Thus, my notion of table, or chair, or desk, is made up of several conceptions, of form, size, material, color, hardness, weight, use, etc., etc., all which, taken together, constitute my notion of the object thus designated.
Originally given as discrete.—These several elements that enter into the composition of our conceptions of objects, it is further to be noticed, are, in the first instance, given us in perception, not as a complex whole, but as discrete elements. Thus, sight gives us form and color; touch gives us extension, hardness, smoothness, etc.; muscular resistance gives us weight, and so, by the various senses, we gather the several properties which make up our cognizance of the object, and which, taken together, constitute our conception of it.