But we need not dwell in the meantime on these and the many other difficulties and riddles presented by our cosmological hypothesis. However these may be solved, a general consideration will remain—namely, that whether the world is governed by law or not, whether it is sufficient unto itself or not, there is a world full of the most diverse phenomena, and there are laws. Whence then have both these come? Is it a matter of course, is it quite obvious that they should exist at all, and that they should be exactly as they are? We do not here appeal without further ceremony to the saying “everything must have a cause, therefore the world also.” It [pg 062] is not absolutely correct. For instance, if the world were so constituted that it would be impossible for it not to exist, that the necessity for its existence and the inconceivability of its non-existence were at once explicit and obvious, then there would be no sense in inquiring after a cause. In regard to a “necessary” thing, if there were any such, we cannot ask, “Why, and from what cause does this exist?” If it was necessary, that implies that to think of it as not existing would be ridiculous, and logically or metaphysically impossible. Unfortunately there are no “necessary” things, so that we cannot illustrate the case by examples. But there are at least necessary truths as distinguished from contingent truths. And thus some light may be brought into the matter for the inexpert. For instance, a necessary truth is contained in the sentence, “Everything is equal to itself,” or, “The shortest distance between two points is a straight line.” We cannot even conceive of the contrary. Therefore these axioms have no reasons, and can neither be deduced nor proved. Every question as to their reasons is quite meaningless. As examples of a “contingent” truth we may take “It rains to-day,” or “The earth revolves round the sun.” For neither one nor the other of these is necessarily so. It is so as a matter of fact, but under other circumstances it might have been otherwise. The contrary can be conceived of and represented, and has in itself an equal degree of possibility. Therefore such a fact requires to [pg 063] be and is capable of being reasoned out. I can and must ask, “How does it happen that it rains to-day? What are the reasons for it?” But as we must seek for sufficient reasons for “contingent” truths, that is, for those of which the contrary was equally possible, so assuredly we must seek for sufficient causes for “contingent” phenomena and events, those which can be thought of as not existing, or as existing in a different form. For these we must find causes and actual reasons. Otherwise they have no foundation. The element of “contingency” must be done away with; they must be shown to result from sufficient causes. That is to say nothing less than that they must be traced back to some necessity. For it is one of the curious fundamental convictions of our reason, and one in which all scientific investigation has its ultimate roots, that what is “contingent” is only apparently so, and in reality is in some way or other based on necessity. Therefore reason seeks causes for everything.
The search for causes involves showing that a thing was necessary. And this must obviously apply to the world as a whole. If it were quite obvious that the world and its existence as it is were necessary, that is, that it would be contrary to reason to think of the world, and its phenomena, and their obedience to law as non-existent, or as different from what they are, all inquiry would be at an end. This would be the ultimate necessity in which all the apparent contingency of isolated phenomena and existences was firmly based. [pg 064] But this is far from being the case. That anything exists, and that the world exists, is for us absolutely the greatest “contingency” of all, and in regard to it we can and must continually ask, “Why does anything exist at all, and why should it not rather be non-existent?” Indeed, all our quest for sufficient causes here reaches its climax. In more detail: that these celestial systems and bodies, the ether, attraction and gravitation should exist, and that everything should be governed by definite laws, all literally “as if shot from a pistol,” there must undoubtedly be some sufficient reason, certain as it is that we shall never discover it. It is true, as some one has said, that we live not only in a very fortuitous world, but in an incredibly improbable one. And this is not affected by the fact that the world is completely governed by law. Law only confirms it. The fact that all details may be clearly and mathematically calculated in no way prevents them from being fundamentally contingent. For they are only so calculable on the basis of the given fundamental characters of the world. And that is precisely the problem: “Why do these characters exist and not quite different ones, and why should any exist at all?”
If any one should say: “Well, we must just content ourselves with recognising the essentially ‘contingent’ nature of existence, for we shall never be able to get beyond that,” he would be right in regard to the second statement. To get beyond that and to see what it is—eternal [pg 065] and in itself necessary—that lies at the basis of this world of “contingency” is indeed impossible. But he would be wrong as to the first part of the assertion. For no one will “content himself.” For that all chance is only apparently chance, and is ultimately based in necessity, is a deeply-rooted and fundamental conviction of our reason, one which directs all scientific investigation, and which cannot be ignored. It demands ceaselessly something necessary as the permanent basis of contingent existence. And this fact is and remains the truth involved in the “cosmological proofs of the existence of God” of former days. It was certainly erroneous to suppose that “God” could be proved. For it is a long way from that “idea of necessity” to religious experience of God. And it was erroneous, too, to suppose that anything could be really “proved.” What is necessary can never really be proved from what is contingent. But the recognition of the contingent nature of the world is a stimulus that stirs up within our reason the idea of the necessary, and it is a fact that reason finds rest only in this idea.