William Osler

“ In the second half of the fifteenth century a new age began in Western Europe. The revival of Greek, the invention of printing, and the discovery of America gave fresh ideas and new prospects to mankind. But, as the sun’s rays were believed to breed serpents in fermenting matter, so amid this ferment of new life and light rose a hideous monster, more terrible than any fabled dragon of romance or superstition of the darkest ages, which for generations satiated itself on the tears and blood of the innocent and helpless. This was the witch mania. ”

“ The scientific spirit will always hesitate to acquiesce in the limits which are set to inquiry by sheer brute facts, and if the absolute truth of certain principles were merely an ultimate fact which could neither be impugned nor explained, this would go far to make these principles appear unintelligible and would be a constant challenge to dispense with them, or somehow to evade them. A principle, then, should always be prepared to state the reasons a science had for adopting it: only the reasons will appear from the actual working of the science. ”

“ For to admit the essential progressiveness of scientific truth and its indefinite capacity for improvement means unlimited freedom to research into truths which are infinitely perfectible, because they are never ‘absolute’. The ideal of the infinite perfectibility of truth, and the infinite progressiveness of science, is more than an adequate substitute for the ‘logical ideal’ which is abandoned. For not only is it an ideal which works, but it really embodies a nobler aspiration than that which represented science as ‘resting’ in absolute perfection on fixed ‘foundations’ of ‘eternal’ truth. ”

“ As a logical ideal also this notion of all-​inclusiveness is absurd. If no inquiry could ever begin until all the facts had been assembled, how could anything be discovered until omniscience had been achieved, i.e. when there was nothing left to discover? For how are we to know that our assembly of ‘facts’ really is complete? And if literally all the facts have to be used as data in any inquiry, shall we not speedily find that every fact ramifies into infinity, and drags in the totality of reality, and a knowledge of all things present, past, and future? ”

“ But just because a logic that recognizes the actual process of discovery does not presume to dictate formal methods to the discoverer, and leaves him a very free hand, it does not relieve him of any of the responsibility for conducting his researches to a prosperous issue. As there is no longer any pretence that any logical machinery can be devised to guarantee success, success and failure become his personal achievements. If he fails, he can no longer plead that it is not his fault, seeing that he has kept every letter of the law and broken no logical rule. ”

“ It is not merely that its maker can have no assurance that his enterprise will succeed, that he cannot start with a feeling of certainty from established truths, and be wafted by an irresistible wave of logical necessity to the safe haven of a predestined conclusion. He must start with a consciousness of ignorance and an all-​pervading feeling of doubt about every step of his inquiry. ”

“ In general, the feelings of doubt, expectancy, and perplexity which beset the mind of the inquirer, and contrast so distinctly with the feelings of confidence, knowledge, certainty, and necessity which accompany a ‘proof’, originate in a logical fact. Every inquiry starts from a problem, of which the solution is not yet known. An inquiry is, as the name implies, a question, put, not to nature at large and at random, but to some part of it, which is taken to be relevant and to contain a possible answer to the inquirer’s question. ”

“ It is more than doubtful whether the notion of an ‘evolution’ of species could ever have been reached, except by starting from the false notion of the fixity of species, or whether the true nature of the mobility and development of meanings could have been understood except by correcting the Platonic theory of immutable and eternal ‘universals’. To ‘proof’ all these incidents and accidents of the history of discovery are irrelevant; all that has to be done is to show that the new truth can be deduced from the old, and that a ‘logical connexion’ exists between them. ”

“ And we have seen (§ 13) that it is not in the end possible to devise a form of proof which is bomb-proof against the attacks of experience and superior to verification.
Is it not wiser, then, to admit that life has its claims upon science, and science upon logic? We simply must have a science that can handle human life and meet human needs, and does not degenerate into a game with arbitrary and fantastic rules which depart from the actual conditions of life in any direction and to any distance unrestrained imagination carries them; and our logic must deign to study such a science. ”

“ Accordingly, the ‘discovery’ of a truth is only the beginning of its career, the first step by which it makes its way in the world, and still very distant from the crowning ‘proof’ with which logic complacently adorns it ex post facto, when it has ‘arrived’. The slowness and difficulty, then, with which the human race makes discoveries, and its blindness to the most obvious facts, if it happens to be unprepared or unwilling to see them, should suffice to show that there is something gravely wrong about the logician’s account of discovery. ”

“ Only in whatever way he fails, his personal failure is pro tanto a failure of science to progress. Every science has somehow to get hold of a clue to guide it through the labyrinth of fact, and this clue has to lead it right, though it need not ‘follow necessarily’ from previous knowledge.
Nevertheless, if, and in so far as, a researcher succeeds in making a discovery, some of his personal credit is reflected upon his methods ex-post facto. Their success does not, of course, establish their formal ‘validity’; but it stops the mouth of those who argued that what is ‘invalid’ must be worthless. ”

“ The ‘facts’ are not all fact. They include unknown, and often large, amounts of prejudice, illusion, error, superstition, and other remnants of the lurid past and stormy youth of every science. It is useless to repine at this inevitable consequence of past history, and childish to try to purge it away by defining as science only what ex hypothesi is free from such contaminations. To restrict the logical interest to science qua science, which is by definition infallible, is to forbid any logical treatment of the sciences we actually possess. ”

“ But it can hardly be wrong to advise the scientific mind to practise hospitality towards new facts, while it is no less fitting to show generosity towards old servants that have done their work and can now advantageously be retired. It is ungrateful to abuse them as ‘errors’, and to despise them with the lofty contempt of the higher knowledge to which they have conducted. And in both cases the truly scientific attitude may be attained if an element of fanaticism is not imported into the conception of truth by attributing to it an absoluteness which no human truth in fact possesses. ”

“ Even where he has started with premisses of the most superior kind, which are generally deemed absolutely self-​evident and certain in themselves, he will still be conscious of a doubt whether they will prove to be the right premisses for his purpose. If they are not, their truth is irrelevant and will lead him astray. In no case, therefore, can he escape the responsibility of choosing the right ones from his limited stock of known truths and familiar ideas, as he contemplates the infinite expanse of possible discovery. In whatever direction he moves, the unknown lies before him ”

“ In Hildegard, as in her fellow mystics, we find that ideas on Nature and Man, the Moral World and the Material Universe, the Spheres, the Winds, and the Humours, Birth and Death, and even on the Soul, the Resurrection of the Dead, and the Nature of God, are not only interdependent, but closely interwoven. Nowadays we are well accustomed to separate our ideas into categories, scientific, ethical, theological, philosophical, and so forth, and we even esteem it a virtue to retain and restrain our thoughts within limits that we deliberately set for them. ”

“ It is really obvious to any critical reflection that when a science appeals to ‘facts’, it is really appealing to the facts as known, or supposed to be known. It cannot from the first presume its knowledge to be absolute, and, pace some of our ‘neo-realists’, ignore the question whether the alleged facts are facts at all, and so pretend to start from ‘the facts as they really are’. ”

“ He will ask, therefore, for evidence that an absolute fixity of terms is the vital necessity for logic it is declared to be. He will admit, of course, the familiar arguments for a certain stability of meanings which have come down from the days of Plato, but he will suggest that a relative fixity of terms is quite sufficient to content them. He will point out that in a progressive science any absolute fixity in its terms is precluded by the very progress of the science. For the terms in use must somehow manage to convey the growing knowledge they are employed to ‘fix’. ”

“ For, however well a theory works, the thought that one may hereafter be found to work better can never logically be excluded. Even if every one alive were perfectly satisfied, and no one could imagine any improvement in an accepted truth—and these conditions are by no means often realized—such psychological considerations would not disprove the logical possibility that the best known was not the best absolutely, and logic would continue to distinguish between a truth that was absolute, and one liable to one billionth chance of error. ”

“ To use military language, the witch mania was an ugly and formidable redoubt connected with other forts and entrenchments. It suffered somewhat from the bombardment by Weyer and Scot, but could only be finally demolished by a general advance of the forces of science and civilization. But if every one had trusted to ‘the spirit of the age’ rather than disturb his neighbours’ beliefs, we might still be burning our grandmothers. ”

“ If, then, we succeed in doing what the natural man will always find difficult, and regard such differences of opinion in a scientific and non-​partisan way, must we not admit that both the conflicting standpoints are inevitable and justifiable? Neither can be pronounced wrong in general and per se, though in regard to a particular problem or occasion either may be. Let us conclude, then, that it may really be a ‘fact’ that the ‘facts’ justify one interpretation and attitude to one mind and another to another. ”