Henry Sidgwick

“ When, in the progress of thought, any prevalent scientific belief is recognised as erroneous, he simply discards this—with more or less endeavour to ascertain the particular causes of error and guard against their recurrence—and, on the whole, continues his natural processes of acquiring, evolving, systematising beliefs with undiminished confidence. But to the philosophical mind the ascertained erroneousness of some beliefs is apt to suggest the possible erroneousness of all. ”

“ For our interest in Kant’s inquiry into the limits of knowledge certainly depends on the fact that the limits which the critical thinker aims at establishing have been actually transgressed by other thinkers. It therefore implies an actual claim to validity on behalf of assertions transgressing the limits which the criticist denies: so that he may be viewed as propounding in respect of these assertions a criterion for distinguishing truth from error, which stamps them as error. ”

“ Around and beneath these more settled portions, in the region where knowledge is growing in range or depth, and the human intellect endeavouring to solve new questions, or penetrate to a more solid basis of principles, we find continually conflict and controversy as to the truth of new conclusions—which appear established and demonstrated to the adventurous minds that have worked them out—as to the legitimacy of new hypotheses, and the validity of new methods; and wherever we find such conflict and controversy, there must be error on one side or the other, or possibly on both. ”

“ To illustrate this, let us take Descartes’ criterion before referred to, as the first that comes to hand in the history of modern philosophy. How can the diversity of the objects of cognition be a logical ground for denying that “what is clearly and distinctly conceived” is necessarily true?—since the distinction between clear and obscure, and between distinct and confused conception, does not become less applicable when we pass from one kind of object to another. ”

“ I have no doubt that “inconceivability of negation,” so understood, is normally an attribute of propositions that appear self-evident truths; I think that, in trying to apprehend distinctly the degree of certainty attaching to any such proposition, we commonly do apply—more or less consciously—Mr. Spencer’s test, and that a systematic application of it is a useful protection against error. But I think that the objection before urged against the infallibility of the Cartesian criterion applies equally to Mr. Spencer’s. ”

“ At any rate, it is the removal of this philosophic uncertainty—in respect of beliefs that, in ordinary thought, are commonly assumed to be true—that I regard as the primary aim of Epistemology.
I have said that this task lies in the way of philosophy; but, I ought to add, that it does not appear to lie in the way of all philosophers. Some of those who have devoted their minds to the solution of philosophical problems seem hardly to have contemplated error except as a kind of misconduct into which the rest of the human race—and especially other philosophers—are inexcusably prone to fall. ”

“ Often in ordinary thought we do not know whether we are sure of what we affirm unless we are led to reflect on the point; sometimes we do not know after reflection; sometimes we are conscious of elements of uncertainty which we decide to disregard, and then we say that we are “morally certain”—meaning that we should unhesitatingly act as if we were certain. This last state of mind I shall consider hereafter; at present I wish to confine attention to beliefs which present themselves in ordinary thought as certain without qualification. ”

“ The theory of chances has been described as a method of extracting knowledge out of ignorance; it is undoubtedly a method of converting probable judgments into certain ones—though the certainty is of a peculiar kind, and its verification presents a special epistemological problem of some interest. But the probable beliefs that I now wish to distinguish from certain ones are beliefs which involve no attempt at a quantitative estimate of ‘amount of probability’ ”

“ It would thus seem that the Critical procedure must presuppose that truth adequately distinguished from error has already been certainly obtained in some departments. And in fact this presupposition is frankly made by Kant so far as Mathematics and Physical Science are concerned. He expressly takes their validity as a datum. Mathematics, he tells us (Proleg., § 40) , “rests on its own evidence,” and Physical Science “on experience and its thorough-going confirmation”: neither study stands in need of Criticism “for its own safety and certainty”. ”

“ But—even if we assume, to limit the discussion, that a man cannot, strictly speaking, observe anything except his own states of consciousness—it still seems paradoxical to affirm that the elimination of all inference from such observation would leave a residuum of certainly true cognition: considering the numerous philosophical disputes that have arisen from the conflicting views taken by different thinkers of psychical experiences supposed to be similar. ”

“ If truth consists—as is admitted—in the agreement of a cognition with its object, that object must, by the true cognition, be distinguished from some other object or objects. Now it is implied in the idea of a general criterion of truth that it is valid with regard to every kind of cognition, whatever the objects cognised may be. ”

“ And the fact of error is still more prominently brought before our minds when we turn from the present to the past, and retrace the history of the now established sciences: since we find that in almost all cases human knowledge has progressed not merely by adding newly ascertained facts to facts previously ascertained, but also, to an important extent, by questioning and correcting or discarding beliefs—often whole systems of connected beliefs—previously held on insufficient grounds. ”

“ It is, indeed, a common experience of mankind in all departments of theory and practice that the liability to error is more equally distributed among human beings than the consciousness of such liability. But the variations of self-confidence that we find among persons who have devoted themselves to the business of philosophy are perhaps less than elsewhere to be attributed to differences of individual temperament: it would rather seem that in the social movement of philosophic thought there are general ebbs and flows ”

“ But no doubt, in elementary study of the positive sciences, error is commonly only brought before our minds in the strictly limited form of slight discrepancy in the results of observation, as something reducible to a minimum by an application of the theory of probabilities. ”

“ Spencer to regard as inconceivable the negation of the independent existence of an external object so far as this is taken to be an aggregate of vivid states of consciousness; especially as he sometimes uses the term “existence beyond consciousness” as an equivalent for the independent non-ego. Are we to take, then, as the fundamental doctrine of Realism, established by the criterion, the proposition that the power manifested in the vivid states exists independently of the power manifested in the faint states? ”

“ So again in Theology, it is the established belief of average members of any religious denomination that the whole world outside the pale of the denomination lies in the darkness of error on some fundamental points ”

“ And no doubt a criterion of this scope is what any philosopher would like to get; but any one who has realised the slow, prolonged, tortuous process by which the human intellect has attained such truth as it has now got, will thankfully accept something less complete. If (e.g.) any epistemological doctrine offers, among the commonly accepted premises of scientific reasoning, to mark out a substantial portion to which the stamp of philosophic certainty may be affixed ”

“ I have contrasted ordinary certitude with philosophic doubt; but even the plain man is not always cocksure. Sometimes he even doubts and suspends his judgment; but even when he believes and positively affirms, many of his beliefs and affirmations—most of those relating to the future—are intended to be taken as not certain but probable. ”

“ At the same time, by the same critical analysis, Kant seeks to stamp with philosophic precision and certitude the fundamental principles of physical knowledge—as that every event has a cause, and the quantum of substance in the physical world is unchangeable—while restricting the application of these principles to phenomena. ”

“ Now, obviously, “if any of these suppositions had been true, the affirmation that I saw my brother would have been erroneous”; but this does not, in Mill’s view, invalidate the Empirical criterion, for “whatever was matter of direct perception, namely, the visual sensations, would have been real”; my apparent cognition of this reality (he tacitly assumes) would have been a true and valid cognition. In short, only separate observation from inference and observation—or apparent knowledge obtained through observation—is absolutely valid and trustworthy ”

“ It may, however, be thought that this need—though undeniably urgent in the case of such studies as, e.g., Politics and Theology—will not be practically presented, so long as the philosopher’s work is confined to the positive sciences. The prevalence of error in Politics is kept prominently before our minds by the system of party government ”

“ It is partly the fact that the philosophic mind of the modern world is now rather at the ebb, with its constructive impulses comparatively feeble, which explains the development and the prominence that the epistemological aspect or function of philosophy is now receiving ”

“ According to my experience, disagreeable sensations, when not too violent, even tend to excite the opposite imagination: e.g., great thirst is apt be attended by a recurrent imagination of cool spring water gurgling down my throat. ”