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 [pg 286] 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 shape of verbal argumentation, determines neither our principles, nor our ultimate judgments,—that it is [pg 287] neither the test of truth, nor the adequate basis of assent.[12]
§ 2. Informal Inference.
It is plain that formal logical sequence is not in fact the method by which we are enabled to become certain of what is concrete; and it is equally plain, from what has been already suggested, what the real and necessary method is. It is the cumulation of probabilities, independent of each other, arising out of the nature and circumstances of the particular case which is under review; probabilities too fine to avail separately, too subtle and circuitous to be convertible into syllogisms, too numerous and various for such conversion, even were they convertible. As a man’s portrait differs from a sketch of him, in having, not merely a continuous outline, but all its details filled in, and shades and colours laid on and harmonized together, such is the multiform and intricate process of ratiocination, necessary for our reaching him as a concrete fact, compared with the rude operation of syllogistic treatment.
Let us suppose I wish to convert an educated, thoughtful Protestant, and accordingly present for his acceptance a syllogism of the following kind:—“All Protestants are bound to join the Church; you are a Protestant: ergo.” He answers, we will say, by [pg 289] denying both premisses; and he does so by means of arguments, which branch out into other arguments, and those into others, and all of them severally requiring to be considered by him on their own merits, before the syllogism reaches him, and in consequence mounting up, taken all together, into an array of inferential exercises large and various beyond calculation. Moreover, he is bound to submit himself to this complicated process from the nature of the case; he would act rashly, if he did not; for he is a concrete individual unit, and being so, is under so many laws, and is the subject of so many predications all at once, that he cannot determine, offhand, his position and his duty by the law and the predication of one syllogism in particular. I mean he may fairly say, “Distinguo,” to each of its premisses: he says, “Protestants are bound to join the Church,—under circumstances,” and “I am a Protestant—in a certain sense;” and therefore the syllogism, at first sight, does not touch him at all.
Before, then, he grants the major, he asks whether all Protestants really are bound to join the Church—are they bound in case they do not feel themselves bound; if they are satisfied that their present religion is a safe one; if they are sure it is true; if, on the other hand, they have grave doubts as to the doctrinal fidelity and purity of the Church; if they are convinced that the Church is corrupt; if their conscience instinctively rejects certain of its doctrines; if history convinces them that the Pope’s power is not jure divino, but merely in the order of Providence? if, again, they are in a heathen country where priests are not? or [pg 290] where the only priest who is to be found exacts of them, as a condition of their reception, a profession, which the Creed of Pope Pius IV. says nothing about; for instance, that the Holy See is fallible even when it teaches, or that the Temporal Power is an anti-Christian corruption? On one or other of such grounds he thinks he need not change his religion; but presently he asks himself, Can a Protestant be in such a state as to be really satisfied with his religion, as he has just now been professing? Can he possibly believe Protestantism came from above, as a whole? how much of it can he believe came from above? and, as to that portion which he feels did come from above, has it not all been derived to him from the Church, when traced to its source? Is not Protestantism in itself a negation? Did not the Church exist before it? and can he be sure, on the other hand, that any one of the Church’s doctrines is not from above? Further, he finds he has to make up his mind what is a corruption, and what are the tests of it; what he means by a religion; whether it is obligatory to profess any religion in particular; what are the standards of truth and falsehood in religion; and what are the special claims of the Church.
And so, again, as to the minor premiss, perhaps he will answer, that he is not a Protestant; that he is a Catholic of the early undivided Church; that he is a Catholic, but not a Papist. Then he has to determine questions about division, schism, visible unity, what is essential, what is desirable; about provisional states; as to the adjustment of the Church’s claims with those of personal judgment and responsibility; as to the soul of [pg 291] the Church contrasted with the body; as to degrees of proof, and the degree necessary for his conversion; as to what is called his providential position, and the responsibility of change; as to the sincerity of his purpose to follow the Divine Will, whithersoever it may lead him; as to his intellectual capacity of investigating such questions at all.