Psychology: Briefer Course

by William James

Call the fact or concrete datum S;
the essential attribute M;
the attribute's property P.

Then the reasoned inference of P from S cannot be made without M's intermediation. The 'essence' M is thus that third or middle term in the reasoning which a moment ago was pronounced essential. For his original concrete S the reasoner substitutes its abstract property M. What is true of M, what is coupled with M, thereupon holds true of S, is coupled with S. As M is properly one of the parts of the entire S, reasoning may then be very well defined as the substitution of parts and their implications or consequences for wholes. And the art of the reasoner will consist of two stages:

First, sagacity, or the ability to discover what part, M, lies embedded in the whole S which is before him;

Second, learning, or the ability to recall promptly M's consequences, concomitants, or implications.

If we glance at the ordinary syllogism—

⁂	M is P;
	S is M;
	S is P

—we see that the second or minor premise, the 'subsumption' as it is sometimes called, is the one requiring the sagacity; the first or major the one requiring the fertility, or fulness of learning. Usually the learning is more apt to be ready than the sagacity, the ability to seize fresh aspects in concrete things being rarer than the ability to learn old rules; so that, in most actual cases of reasoning, the minor premise, or the way of conceiving the subject, is the one that makes the novel step in thought. This is, to be sure, not always the case; for the fact that M carries P with it may also be unfamiliar and now formulated for the first time.

The perception that S is M is a mode of conceiving S. The statement that M is P is an abstract or general proposition. A word about both is necessary.

What is meant by a Mode of Conceiving.—When we conceive of S merely as M (of vermilion merely as a mercury-compound, for example), we neglect all the other attributes which it may have, and attend exclusively to this one. We mutilate the fulness of S's reality. Every reality has an infinity of aspects or properties. Even so simple a fact as a line which you trace in the air may be considered in respect to its form, its length, its direction, and its location. When we reach more complex facts, the number of ways in which we may regard them is literally endless. Vermilion is not only a mercury-compound, it is vividly red, heavy, and expensive, it comes from China, and so on, ad infinitum. All objects are well-springs of properties, which are only little by little developed to our knowledge, and it is truly said that to know one thing thoroughly would be to know the whole universe. Mediately or immediately, that one thing is related to everything else; and to know all about it, all its relations need be known. But each relation forms one of its attributes, one angle by which some one may conceive it, and while so conceiving it may ignore the rest of it. A man is such a complex fact. But out of the complexity all that an army commissary picks out as important for his purposes is his property of eating so many pounds a day; the general, of marching so many miles; the chair-maker, of having such a shape; the orator, of responding to such and such feelings; the theatre-manager, of being willing to pay just such a price, and no more, for an evening's amusement. Each of these persons singles out the particular side of the entire man which has a bearing on his concerns, and not till this side is distinctly and separately conceived can the proper practical conclusions for that reasoner be drawn; and when they are drawn the man's other attributes may be ignored.