While absolute chance cannot be admitted, partly because we are not in need of it, (since the irregularities of nature can be sufficiently explained otherwise,) and partly because the idea of absolute chance if it were needed, is incompatible with our world-conception, we shall, nevertheless, have to concede to chance, as we understand the term, a very important rôle in the evolution of life. The formation of worlds and the history of mankind depend to a great extent upon chances similar to the throws of dice. There are many possibilities, and now this, now that, will, according to the circumstances, be realised—of course in each case with strict necessity. Let us illustrate this idea by an example. The formation of about seventy elements out of the original world-substance, which may be supposed to be homogeneous, does not appear to depend upon chance. Their universal appearance in all parts of the universe suggests the hypothesis that their formation is the inevitable result of a gradual condensation of nebular substances. We find everywhere, according to the stage of condensation, a gradual appearance, first of the lighter, then of the heavier elements. There seems to be no possibility of the formation of other elements than those known to us (including here the hypothetical elements which are still missing in the Mendeljeff series and at the same time, at least, not excluding a further continuance of the series). These elements or none, it appears, must be formed out of the original substance of our world. Let us here assume, for argument’s sake, that it were so beyond question, and that we knew the nature of the world-substance to be such as to condense, if it condenses at all, into no other but these forms, which we call chemical elements. This would be a limitation of possibilities. Exactly so the throws Of dice are limited. With the dice commonly in use we cannot throw fractions; nor can we throw either zero, or seven, or any other higher number. We can throw only whole numbers, integrals from one up to six. But while we thus assume that the formation of the elements is limited to those actually existing, the proportion in which the elements may be distributed in the different nebulæ and solar systems, is apparently very different. Suppose we had a full knowledge of the intrinsic nature of the world-substance and were standing outside the universe observing the process of world-formations; we could not from this knowledge alone predict all that would happen. We should on our assumption be able to predict _a priori_ that such elements would be formed. But whether the different elements would be generated in these or in other proportions appears to depend upon the presence of certain conditions, perhaps the rapidity of motion, the heat produced by friction, the temperature of the surrounding cosmic space, any knowledge of which is not included in our knowledge of the nature of the world-substance. These conditions