Little Masterpieces of Science: Mind

by Unknown

Now, in so far as our conscious mental activity is under the direction of our will, we can improve this form of common sense, as to both its range and the trustworthiness of its judgments, by appropriate training. Such training, as regards the purely intellectual aspect of common sense, will consist in the determinate culture of the habit of honestly seeking for truth,—dismissing prejudice, setting aside self-interest, searching out all that can be urged on each side of the question at issue, endeavouring to assign to every fact and argument its real value, and then weighing the two aggregates against each other with judicial impartiality. For in proportion to the steadiness with which this course is volitionally pursued, must be its effectiveness in shaping the mechanism whose automatic action constitutes the unconscious thinking, of which the results express themselves in our common-sense judgments.

The ordinary common sense of mankind, disciplined and enlarged by an appropriate culture, becomes one of the most valuable instruments of scientific inquiry; affording in many instances the best and sometimes the only basis for a rational conclusion. A typical case, in which no special knowledge is required, is afforded by the flint implements of the Abbeville and Amiens gravel beds. No logical proof can be adduced that the peculiar shapes of these flints were given to them by human hands; but no unprejudiced person who has examined them now doubts it.

The evidence of design to which, after an examination of one or two such specimens, we should only be justified in attaching a probable value, derives an irresistible cogency from accumulation. On the other hand, the improbability that these flints acquired their peculiar shape by accident, becomes to our minds greater and greater as more and more such specimens are found; until at last this hypothesis, although it cannot be directly disproved, is felt to be almost inconceivable, except by minds previously possessed by the dominant idea of the modern origin of man. And thus what was in the first instance a matter of discussion, has now become one of those self-evident propositions, which claim the unhesitating assent of all whose opinion on the subject is entitled to the least weight.

We proceed upwards, however, from such questions as the common sense of mankind generally is competent to decide, to those in which special knowledge is required to give value to the judgment; and here we must distinguish between those departments of inquiry in which scientific conclusions are arrived at by a process of strict reasoning, and those in which they partake of the nature of common sense judgments.

Of the former class we have a typical example in mathematics, and in those exact sciences which make use of mathematics as their instrument of proof; but even in these, it is common sense which affords not only the basis, but the materials of the fabric. For while the axioms of geometry are self-evident truths which not only do not require proof, but are not capable of being proved in all their universality, every step of a demonstration is an assertion of which our acceptance depends on our incapability of conceiving either the contrary or anything else than the thing asserted. And thus the certain assurance of the proof felt by every person capable of understanding a mathematical demonstration, depends upon the conclusive self-evidence of each step of it. But we not unfrequently meet with individuals, not deficient in ordinary common sense, who cannot be brought to see this self-evidence; whilst, on the other hand, the advanced mathematician, when adventuring into new paths of inquiry, is able to take a great deal for granted as self-evident, which at an earlier stage of his researches would not have so presented itself to his mind. The deliverances of this acquired intuition can in most cases be readily justified by the reasoning process which they have anticipated. But the genius of a mathematician—that is, his special aptitude developed by special culture—will occasionally enable him to divine a truth, of which, though he may be able to prove it experientially, neither he nor any other can at the time furnish a logical demonstration. In this divining power we have clear evidence of the existence of a capacity which cannot be accounted for by the mere co-ordination of antecedent experiences, whether of the individual or of the race; and yet, as already shown, such co-ordination has furnished the stimulus to its development.

Of those departments of science, on the other hand, in which our conclusions rest (like those of ordinary common sense) not on any one set of experiences, but upon our unconscious co-ordination of the whole aggregate of our experiences,—not on the conclusiveness of any one train of reasoning, but on the convergence of all our lines of thought towards one centre,—geology may be taken as a typical example. For this inquiry brings (as it were) into one focus, the light afforded by a great variety of studies,—physical and chemical, geographical and biological; and throws it on the pages of that great stone book in which the past history of our globe is recorded. And its real progress dates from the time when that common sense method of interpretation came to be generally adopted, which consists in seeking the explanation of past changes in the forces at present in operation, instead of invoking (as the older geologists were wont to do) the aid of extraordinary and mysterious agencies.

Of the adequacy of common sense to arrive at a decisive judgment under the guidance of the convergence just indicated, we have a good example in the following occurrence:—A man having had his pocket picked of a purse, and the suspected thief having been taken with a purse upon him, the loser was asked if he could swear to it as his property. This he could not do; but as he was able to name not only the precise sum which the purse contained, but also the pieces of money of which that sum consisted, the jury unhesitatingly assigned to him the ownership of the purse and its contents. A mathematician could have calculated, from the number of coins, what were the chances against the correctness of a mere guess; but no such calculation could have added to the assurance afforded by common sense, that the man who could tell not only the number of coins in the purse, but the value of each one of them, must have been its possessor.

Familiar instances of the like formation of a basis of judgment by the unconscious co-ordination of experiences, will be found in many occurrences of daily life; in which the effect of special training manifests itself in the formation of decisions, that are not the less to be trusted because they do not rest on assignable reasons:—Thus, a literary man, who has acquired by culture the art of writing correctly and forcibly, without having ever formally studied either grammar, the logical analysis of sentences, or the artifices of rhetoric, will continually feel in criticizing his own writings or those of others, that there is something faulty in style or construction, and may be able to furnish the required correction, whilst altogether unable to say in what the passage is wrong, or why his amendment sets it right. Or, to pass into an entirely different sphere, a practised detective will often arrive, by a sort of divination, at a conviction of the guilt or innocence of a suspected person, which ultimately turns out to be correct; and yet he could not convey to another any adequate reasons for his assurance, which depends upon the impression made upon his mind by minute details of look, tone, gesture, or manner, which have little or no significance to ordinary observers, but which his specially cultured common sense instinctively apprehends.

But in the ordinary affairs of life, our common sense judgments are so largely influenced by the emotional part of our nature—our individual likes and dislikes, the predominance of our selfish or of our benevolent affections, and so on,—that their value will still more essentially depend upon the earnestness and persistency of our self-direction towards the right.[4] The more faithfully, strictly, and perseveringly we try to disentangle ourselves from all selfish aims, all conscious prejudices, the more shall we find ourselves progressively emancipated from those unconscious prejudices, which cling around us as results of early misdirection and habits of thought and which (having become embodied in our organization) are more dangerous than those against which we knowingly put ourselves on guard. And so, in proportion to the degree in which we habituate ourselves to try every question by first principles, rather than by the supposed dictates of a temporary expediency, will the mechanism of our unconscious thinking form itself in accordance with those principles, so often as to evolve results which satisfy both ourselves and others with their self-evident truthfulness and rectitude. It has been well remarked by a man of large experience of human nature and action, that the habitual determination to do the right thing, marvellously clears the judgment as to matters purely intellectual or prudential, having in themselves no moral bearing.

Of this we have a good illustration in the advice which an eminent and experienced judge (the story is told of Lord Mansfield) is said to have given to a younger friend, newly appointed to a colonial judgeship:—“Never give reasons for your decisions; your judgments will very probably be right, but your reasons will almost certainly be wrong.” The meaning of this may be taken to be:—“Your legal instinct, or specially trained common sense, based on your general knowledge of law, guided by your honesty of intention, will very probably lead you to correct conclusions; but your knowledge of the technicalities of law is not sufficient to enable you to give reasons for these conclusions, which shall bear the test of hostile scrutiny.”