The chief of these purposes is predication, a theoretic function which, though it always leads eventually to some kind of action, yet tends as often as not to inhibit the immediate motor response to which the simple inferences of which we have been speaking give rise. In reasoning, A may suggest B; but B, instead of being an idea which is simply obeyed by us, is an idea which suggests the distinct additional idea C. And where the train of suggestion is one of reasoning distinctively so called as contrasted with mere revery or 'associative' sequence, the ideas bear certain inward relations to each other which we must proceed to examine with some care.
The result C yielded by a true act of reasoning is apt to be a thing voluntarily sought, such as the means to a proposed end, the ground for an observed effect, or the effect of an assumed cause. All these results may be thought of as concrete things, but they are not suggested immediately by other concrete things, as in the trains of simply associative thought. They are linked to the concretes which precede them by intermediate steps, and these steps are formed by general characters articulately denoted and expressly analyzed out. A thing inferred by reasoning need neither have been an habitual associate of the datum from which we infer it, nor need it be similar to it. It may be a thing entirely unknown to our previous experience, something which no simple association of concretes could ever have evoked. The great difference, in fact, between that simpler kind of rational thinking which consists in the concrete objects of past experience merely suggesting each other, and reasoning distinctively so called, is this, that whilst the empirical thinking is only reproductive, reasoning is productive. An empirical, or 'rule-of-thumb,' thinker can deduce nothing from data with whose behavior and associates in the concrete he is unfamiliar. But put a reasoner amongst a set of concrete objects which he has neither seen nor heard of before, and with a little time, if he is a good reasoner, he will make such inferences from them as will quite atone for his ignorance. Reasoning helps us out of unprecedented situations—situations for which all our common associative wisdom, all the 'education' which we share in common with the beasts, leaves us without resource.
Let us make this ability to deal with novel data the technical differentia of reasoning. This will sufficiently mark it out from common associative thinking, and will immediately enable us to say just what peculiarity it contains.
It contains analysis and abstraction. Whereas the merely empirical thinker stares at a fact in its entirety, and remains helpless, or gets 'stuck,' if it suggests no concomitant or similar, the reasoner breaks it up and notices some one of its separate attributes. This attribute he takes to be the essential part of the whole fact before him. This attribute has properties or consequences which the fact until then was not known to have, but which, now that it is noticed to contain the attribute, it must have.
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, then 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,[325] 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.[326]
If we glance at the ordinary syllogism—
M is P;
S is M;
Therefore 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.