Grammar of Assent

So, too, as regards Induction and Analogy, as modes of Inference; for, whether I argue, "This place will have the cholera, unless it is drained; for there are a number of well-ascertained cases which point to this conclusion;" or, "The sun will rise tomorrow, for it rose today;" in either method of reasoning I appeal, in order to prove a particular case, to a general principle or law, which has not force enough to warrant more than a probable conclusion. As to the cholera, the place in question may have certain antagonist advantages, which anticipate or neutralize the miasma which is the principle of the poison; and as to the sun's rising tomorrow, there was a first day of the sun's rising, and therefore there may be a last.

This is what I have to say on formal Inference, when taken to represent Ratiocination. Science in all its departments has too much simplicity and exactness, from the nature of the case, to be the measure of fact. In its very perfection lies its incompetency to settle particulars and details. As to Logic, its chain of conclusions hangs loose at both ends; both the point from which the proof should start, and the points at which it should arrive, are beyond its reach; it comes short both of first principles and of concrete issues. Even its most elaborate exhibitions fail to represent adequately the sum-total of considerations by which an individual mind is determined in its judgment of things; even its most careful combinations made to bear on a conclusion want that steadiness of aim which is necessary for hitting it. As I said when I began, thought is too keen and manifold, its sources are too remote and hidden, its path too personal, delicate, and circuitous, its subject-matter too various and intricate, to admit of the trammels of any language, of whatever subtlety and of whatever compass.

Nor is it any disparagement of the proper value of formal reasonings thus to speak of them. That they cannot proceed beyond probabilities is most readily allowed by those who use them most. Philosophers, experimentalists, lawyers, in their several ways, have commonly the reputation of being, at least on moral and religious subjects, hard of belief; because, proceeding in the necessary investigation by the analytical method of verbal inference, they find within its limits no sufficient resources for attaining a conclusion. Nay, they do not always find it possible in their own special province severally; for, even when in their hearts they have no doubt about a conclusion, still often, from the habit of their minds, they are reluctant to own it, and dwell upon the deficiencies of the evidence, or the possibility of error, because they speak by rule and by book, though they judge and determine by common-sense.

Every exercise of nature or of art is good in its place; and the uses of this logical inference are manifold. It is the great principle of order in our thinking; it reduces a chaos into harmony; it catalogues the accumulations of knowledge; it maps out for us the relations of its separate departments; it puts us in the way to correct its own mistakes. It enables the independent intellects of many, acting and re-acting on each other, to bring their collective force to bear upon one and the same subject-matter, or the same question. If language is an inestimable gift to man, the logical faculty prepares it for our use. Though it does not go so far as to ascertain truth, still it teaches us the direction in which truth lies, and how propositions lie towards each other. Nor is it a slight benefit to know what is probable, and what is not so, what is needed for the proof of a point, what is wanting in a theory, how a theory hangs together, and what will follow, if it be admitted. Though it does not itself discover the unknown, it is one principal way by which discoveries are made. Moreover, a course of argument, which is simply conditional, will point out when and where experiment and observation should be applied, or testimony sought for, as often happens both in physical and legal questions. A logical hypothesis is the means of holding facts together, explaining difficulties, and reconciling the imagination to what is strange. And, again, processes of logic are useful as enabling us to get over particular stages of an investigation speedily and surely, as on a journey we now and then gain time by travelling by night, make short cuts when the high-road winds, or adopt water-carriage to avoid fatigue.

But reasoning by rule and in words is too natural to us, to admit of being regarded merely in the light of utility. Our inquiries spontaneously fall into scientific sequence, and we think in logic, as we talk in prose, without aiming at doing so. However sure we are of the accuracy of our instinctive conclusions, we as instinctively put them into words, as far as we can; as preferring, if possible, to have them in an objective shape which we can fall back upon,—first for our own satisfaction, then for our justification with others. Such a tangible defence of what we hold, inadequate as it necessarily is, considered as an analysis of our ratiocination in its length and breadth, nevertheless is in such sense associated with our holdings, and so fortifies and illustrates them, that it acts as a vivid apprehension acts, giving them luminousness and force. Thus inference becomes a sort of symbol of assent, and even bears upon action.

I have enlarged on these obvious considerations, lest I should seem paradoxical; but they do not impair the main position of this Section, that Inference, considered in the sense of verbal argumentation, determines neither our principles, nor our ultimate judgments,—that it is neither the test of truth, nor the adequate basis of assent [Note].

Section 2

1. I have assumed throughout this Section that all verbal argumentation is ultimately syllogistic; and in consequence that it ever requires universal propositions and comes short of concrete fact. A friend refers me to the dispute between Des Cartes and Gassendi, the latter maintaining against the former that "Cogito ergo sum" implies the universal "All who think exist." I should deny this with Des Cartes; but I should say (as indeed he said), that his dictum was not an argument, but was the expression of a ratiocinative instinct, as I explain below under the head of "Natural Logic."

As to the instance "Brutes are not men; therefore men are not brutes," there seems to me no consequence here, neither a præter nor a propter, but a tautology. And as to "It was either Tom or Dick that did it; it was not Dick, ergo," this may be referred to the one great principle on which all logical reasoning is founded, but really it ought not to be accounted an inference any more that if I broke a biscuit, flung half away, and then said of the other half, "This is what remains." It does but state a fact. So, when the 1st, 2nd, or 3rd proposition of Euclid II, is put before the eyes in a diagram, a boy, before he yet has learned to reason, sees with his eyes the fact of the thesis, and this seeing it even makes it difficult for him to master the mathematical proof. Here, then, a fact is stated in the form of an argument.

However, I have inserted parentheses at pp. 278 and 283, in order to say " transeat" to the question.