An Essay in Aid of a Grammar of Assent

by John Henry Newman

Such is ratiocination, in what may be called a state of nature, as it is found in the uneducated,—nay, in all men, in its ordinary exercise; nor is there any antecedent ground for determining that it will not be as correct in its informations as it is instinctive, as trustworthy as are sensible perception and memory, though its informations are not so immediate and have a wider range. By means of sense we gain knowledge directly; by means of reasoning we gain it indirectly, that is, by virtue of a previous knowledge. And if we may justly regard the universe, according to the meaning of the word, as one whole, we may also believe justly that to know one part of it is necessarily to know much more than that one part. This thought leads us to a further view of ratiocination. The proverb says, “Ex pede Herculem;” and we have actual experience how the practised zoologist can build up some intricate organization from [pg 261] the sight of its smallest bone, evoking the whole as if it were a remembrance; how, again, a philosophical antiquarian, by means of an inscription, interprets the mythical traditions of former ages, and makes the past live; and how a Columbus is led, from considerations which are common property, and fortuitous phenomena which are successively brought to his notice, to have such faith in a western world, as willingly to commit himself to the terrors of a mysterious ocean in order to arrive at it. That which the mind is able thus variously to bring together into unity, must have some real intrinsic connexion of part with part. But if this summa rerum is thus one whole, it must be constructed on definite principles and laws, the knowledge of which will enlarge our capacity of reasoning about it in particulars;—thus we are led on to aim at determining on a large scale and on system, what even gifted or practised intellects are only able by their own personal vigour to reach piece-meal and fitfully, that is, at substituting scientific methods, such as all may use, for the action of individual genius.

There is another reason for attempting to discover an instrument of reasoning (that is, of gaining new truths by means of old), which may be less vague and arbitrary than the talent and experience of the few or the common-sense of the many. As memory is not always accurate, and has on that account led to the adoption of writing, as being a memoria technica, unaffected by the failure of mental impressions,—as our senses at times deceive us, and have to be corrected by each other; so is it also with our reasoning faculty. The conclusions of one man are [pg 262] not the conclusions of another; those of the same man do not always agree together; those of ever so many who agree together may differ from the facts themselves, which those conclusions are intended to ascertain. In consequence it becomes a necessity, if it be possible, to analyze the process of reasoning, and to invent a method which may act as a common measure between mind and mind, as a means of joint investigation, and as a recognized intellectual standard,—a standard such as to secure us against hopeless mistakes, and to emancipate us from the capricious ipse dixit of authority.

As the index on the dial notes down the sun’s course in the heavens, as a key, revolving through the intricate wards of the lock, opens for us a treasure-house, so let us, if we can, provide ourselves with some ready expedient to serve as a true record of the system of objective truth, and an available rule for interpreting its phenomena; or at least let us go as far as we can in providing it. One such experimental key is the science of geometry, which, in a certain department of nature, substitutes a collection of true principles, fruitful and interminable in consequences, for the guesses, pro re natâ, of our intellect, and saves it both the labour and the risk of guessing. Another far more subtle and effective instrument is algebraical science, which acts as a spell in unlocking for us, without merit or effort of our own individually, the arcana of the concrete physical universe. A more ambitious, because a more comprehensive contrivance still, for interpreting the concrete world is the method of logical inference. What we desiderate is something which may supersede the need of personal [pg 263] gifts by a far-reaching and infallible rule. Now, without external symbols to mark out and to steady its course, the intellect runs wild; but with the aid of symbols, as in algebra, it advances with precision and effect. Let then our symbols be words: let all thought be arrested and embodied in words. Let language have a monopoly of thought; and thought go for only so much as it can show itself to be worth in language. Let every prompting of the intellect be ignored, every momentum of argument be disowned, which is unprovided with an equivalent wording, as its ticket for sharing in the common search after truth. Let the authority of nature, common-sense, experience, genius, go for nothing. Ratiocination, thus restricted and put into grooves, is what I have called Inference, and the science, which is its regulating principle, is Logic.

The first step in the inferential method is to throw the question to be decided into the form of a proposition; then to throw the proof itself into propositions, the force of the proof lying in the comparison of these propositions with each other. When the analysis is carried out fully and put into form, it becomes the Aristotelic syllogism. However, an inference need not be expressed thus technically; an enthymeme fulfils the requirements of what I have called Inference. So does any other form of words with the mere grammatical expressions, “for,” “therefore,” “supposing,” “so that,” “similarly,” and the like. Verbal reasoning, of whatever kind, as opposed to mental, is what I mean by inference, which differs from logic only inasmuch as logic is its scientific form. And it will be more convenient here to [pg 264] use the two words indiscriminately, for I shall say nothing about logic which does not in its substance also apply to inference.

Logical inference, then, being such, and its office such as I have described, the question follows, how far it answers the purpose for which it is used. It proposes to provide both a test and a common measure of reasoning; and I think it will be found partly to succeed and partly to fail; succeeding so far as words can in fact be found for representing the countless varieties and subtleties of human thought, failing on account of the fallacy of the original assumption, that whatever can be thought can be adequately expressed in words.

In the first place, Inference, being conditional, is hampered with other propositions besides that which is especially its own, that is, with the premisses as well as the conclusion, and with the rules connecting the latter with the former. It views its own proper proposition in the medium of prior propositions, and measures it by them. It does not hold a proposition for its own sake, but as dependent upon others, and those others it entertains for the sake of the conclusion. Thus it is practically far more concerned with the comparison of propositions, than with the propositions themselves. It is obliged to regard all the propositions, with which it has to do, not so much for their own sake, as for the sake of each other, as regards the identity or likeness, independence or dissimilarity, which has to be mutually predicated of them. It follows from this, that the more simple and definite are the words of a proposition, and the narrower their meaning, and the more that meaning [pg 265] in each proposition is restricted to the relation which it has to the words of the other propositions compared with it,—in other words, the nearer the propositions concerned in the inference approach to being mental abstractions, and the less they have to do with the concrete reality, and the more closely they are made to express exact, intelligible, comprehensible, communicable notions, and the less they stand for objective things, that is, the more they are the subjects, not of real, but of notional apprehension,—so much the more suitable do they become for the purposes of Inference.

Hence it is that no process of argument is so perfect, as that which is conducted by means of symbols. In Arithmetic 1 is 1, and just 1, and never anything else but 1; it never is 2, it has no tendency to change its meaning, and to become 2; it has no portion, quality, admixture of 2 in its meaning. And 6 under all circumstances is 3 times 2, and the sum of 2 and 4; nor can the whole world supply anything to throw doubt upon these elementary positions. It is not so with language. Take, by contrast, the word “inference,” which I have been using: it may stand for the act of inferring, as I have used it; or for the connecting principle, or inferentia, between premisses and conclusions; or for the conclusion itself. And sometimes it will be difficult, in a particular sentence, to say which it bears of these three senses. And so again in Algebra, a is never x, or anything but a, wherever it is found; and a and b are always standard quantities, to which x and y are always to be referred, and by which they are always to be measured. In Geometry again, the subjects of argument, points, lines, [pg 266] and surfaces, are precise creations of the mind, suggested indeed by external objects, but meaning nothing but what they are defined to mean: they have no colour, no motion, no heat, no qualities which address themselves to the ear or to the palate; so that, in whatever combinations or relations the words denoting them occur, and to whomsoever they come, those words never vary in their meaning, but are just of the same measure and weight at one time and at another.

What is true of Arithmetic, Algebra, and Geometry, is true also of Aristotelic argumentation in its typical modes and figures. It compares two given words separately with a third, and then determines how they stand towards each other, in a bona fide identity of sense. In consequence, its formal process is best conducted by means of symbols, A, B, and C. While it keeps to these, it is safe; it has the cogency of mathematical reasoning, and draws its conclusions by a rule as unerring as it is blind.

Symbolical notation, then, being the perfection of the syllogistic method, it follows that, when words are substituted for symbols, it will be its aim to circumscribe and stint their import as much as possible, lest perchance A should not always exactly mean A, and B mean B; and to make them, as much as possible, the calculi of notions, which are in our absolute power, as meaning just what we choose them to mean, and as little as possible the tokens of real things, which are outside of us, and which mean we do not know how much, but so much certainly as may run away with us, in proportion as we enter into them, beyond the range of [pg 267] scientific management. The concrete matter of propositions is a constant source of trouble to syllogistic reasoning, as marring the simplicity and perfection of its process. Words, which denote things, have innumerable implications; but in inferential exercises it is the very triumph of that clearness and hardness of head, which is the characteristic talent for the art, to have stripped them of all these connatural senses, to have drained them of that depth and breadth of associations which constitute their poetry, their rhetoric, and their historical life, to have starved each term down till it has become the ghost of itself, and everywhere one and the same ghost, “omnibus umbra locis,” so that it may stand for just one unreal aspect of the concrete thing to which it properly belongs, for a relation, a generalization, or other abstraction, for a notion neatly turned out of the laboratory of the mind, and sufficiently tame and subdued, because existing only in a definition.

Thus it is that the logician for his own purposes, and most usefully as far as those purposes are concerned, turns rivers, full, winding, and beautiful, into navigable canals. To him dog or horse is not a thing which he sees, but a mere name suggesting ideas; and by dog or horse universal he means, not the aggregate of all individual dogs or horses brought together, but a common aspect, meagre but precise, of all existing or possible dogs or horses, which all the while does not really correspond to any one single dog or horse out of the whole aggregate. Such minute fidelity in the representation of individuals is neither necessary nor possible to his art; his business is not to ascertain facts in the concrete, [pg 268] but to find and dress up middle terms; and, provided they and the extremes which they go between are not equivocal, either in themselves or in their use, and he can enable his pupils to show well in a vivâ voce disputation, or in a popular harangue, or in a written dissertation, he has achieved the main purpose of his profession.