Chapter LXXXIX: Section XI: Limits of Our Knowledge

You will tell me that our philosopher has clipped his wings, in order to strengthen his legs. Certainly; and he has acted wisely. Experience limits the career which it opens to us; it has given us our goal, but also our boundaries. We have only to observe the elements of which our experience is composed, and the facts from which it sets out, to understand that its range is limited. Its nature and its method confine its progress to a few steps. And, in the first place,[425] the ultimate laws of nature cannot be less numerous than the several distinct species of our sensations. We can easily reduce a movement to another movement, but not the sensation of heat to that of smell, or of color, or of sound, nor either of these to a movement. We can easily connect together phenomena of different degrees, but not phenomena differing in species. We find distinct sensations at the bottom of all our knowledge, as simple indecomposable elements, separated absolutely one from another, absolutely incapable of being reduced one to another. Let experience do what she will, she cannot suppress these diversities which constitute her foundation. On the other hand, experience, do what she will, cannot escape from the conditions under which she acts. Whatever be her province, it is bounded by time and space; the fact which she observes is limited and influenced by an infinite number of other facts to which she cannot attain. She is obliged to suppose or recognize some primordial condition from whence she starts, and which she does not explain.[426] Every problem has its accidental or arbitrary data: we deduce the rest from these, but there is nothing from which these can be deduced. The sun, the earth, the planets, the initial impulse of the heavenly bodies, the primitive chemical properties of substances, are such data.[427] If we possessed them all we could explain everything by them, but we could not explain these themselves. Mill says:

"Why these particular natural agents existed originally and no others, or why they are commingled in such and such proportions, and distributed in such and such a manner throughout space, is a question we cannot answer. More than this: we can discover nothing regular in the distribution itself; we can reduce it to no uniformity, to no law. There are no means by which, from the distribution of these causes, or agents, in one part of space, we could conjecture whether a similar distribution prevails in another."[428]

And astronomy, which just now afforded us the model of a perfect science, now affords us an example of a limited science. We can predict the numberless positions of all the planetary bodies; but we are obliged to assume, beside the primitive impulse and its amount, not only the force of attraction and its law, but also the masses and distances of all the bodies in question. We understand millions of facts, but it is by means of a hundred facts which we do not comprehend; we arrive at necessary results, but it is only by means of accidental antecedents; so that if the theory of our universe were completed there would still remain two great voids: one at the commencement of the physical world, the other at the beginning of the moral world; the one comprising the elements of being, the other embracing the elements of experience; one containing primary sensations, the other primitive agents. "Our knowledge," says Royer-Collard, "consists in tracing ignorance as far back as possible."

Can we at least affirm that these irreducible data are so only in appearance, and in relation to our mind? Can we say that they have causes, like the derived facts of which they are the causes? Can we conclude that every event, always and everywhere, happens according to laws, and that this little world of ours, so well-regulated, is a sort of epitome of the universe? Can we by aid of the axioms, quit our narrow confines, and affirm anything of the universe? In no wise; and it is here that Mill pushes his principles to their furthest consequences: for the law which attributes a cause to every event, has to him no other foundation, worth, or scope, than what it derives from experience. It has no inherent necessity; it draws its whole authority from the great number of cases in which we have recognized it to be true; it only sums up a mass of observations; it unites two data, which, considered in themselves, have no intimate connection; it joins antecedents generally to consequents generally, just as the law of gravitation joins a particular antecedent to a particular consequent; it determines a couple, as do all experimental laws, and shares in their uncertainty and in their restrictions. Listen to this bold assertion:

"I am convinced that anyone accustomed to abstraction and analysis, who will fairly exert his faculties for the purpose, will, when his imagination has once learnt to entertain the notion, find no difficulty in conceiving that in some one, for instance, of the many firmaments into which sidereal astronomy now divides the universe, events may succeed one another at random, without any fixed law; nor can anything in our experience, or in our mental nature, constitute a sufficient, or indeed any, reason for believing that this is nowhere the case. The grounds, therefore, which warrant us in rejecting such a supposition with respect to any of the phenomena of which we have experience, must be sought elsewhere than in any supposed necessity of our intellectual faculties."[429]

Practically, we may trust in so well-established a law; but

"In distant parts of the stellar regions, where the phenomena may be entirely unlike those with which we are acquainted, it would be folly to affirm confidently that this general law prevails, any more than those special ones which we have found to hold universally on our own planet. The uniformity in the succession of events, otherwise called the law of causation, must be received not as a law of the universe, but of that portion of it only which is within the range of our means of sure observation, with a reasonable degree of extension to adjacent cases. To extend it further is to make a supposition without evidence, and to which, in the absence of any ground from experience for estimating its degree of probability, it would be idle to attempt to assign any."[430]

We are, then, irrevocably driven back from the infinite: our faculties and our assertions cannot attain to it; we remain confined in a small circle; our mind reaches not beyond its experience; we can establish no universal and necessary connection between facts; such a connection probably does not even exist. Mill stops here; but certainly, by carrying out his idea to its full extent, we should arrive at the conception of the world as a mere collection of facts; no internal necessity would induce their connection or their existence; they would be simple, arbitrary, accidentally-existing facts. Sometimes, as in our system, they would be found assembled in such a manner as to give rise to regular recurrences; sometimes they would be so assembled that nothing of the sort would occur. Chance, as Democritus taught, would be at the foundation of all things. Laws would be the result of chance, and sometimes we should find them, sometimes not. It would be with existences as with numbers--decimal fractions, for instance, which, according to the chance of their two primitive factors, sometimes recur regularly, and sometimes not. This is certainly an original and lofty conception. It is the final consequence of the primitive and dominant idea, which we have discovered at the beginning of the system, which has transformed the theories of Definition, of Propositions, and of the Syllogism; which has reduced axioms to experimental truths; which has developed and perfected the theory of induction; which has established the goal, the limits, the province, and the methods of science; which everywhere, in nature and in science, has suppressed interior connections; which has replaced the necessary by the accidental; cause by antecedent; and which consists in affirming that every assertion which is not merely verbal forms in effect a couple, that is to say, joins together two facts which were separate by their nature.