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 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 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