The alternative is Blind Chance; and the author, after considering the question, agrees, as again most reasonable persons will agree, that Blind Chance is no explanation of things as they are. He quotes a modern chemist who, discussing the probability of the environmental fitness of the earth for life being a mere chance process, remarks: "There is, in truth, not one chance in countless millions of millions that the many unique properties of carbon, hydrogen, and oxygen, and especially of their stable compounds, water and carbonic acid, which chiefly make up the atmosphere of a new planet, should simultaneously occur in the three elements otherwise than through the operation of a natural law which somehow connects them together. There is no greater probability that these unique properties should be without due cause uniquely favourable to the organic mechanism" (J. J. Henderson, 1913). If neither of the classic points of view is tenable, what then is the explanation, if, indeed, any be possible? The author casts one brief glance down that blind-alley marked "Element Way." Does some known element or some unknown element, to which the name _Bion_ might be given, exist and form the source of the energy in living things? Radium has only been known to us for a few years; can we say that there is no such thing as Bion? Of course we cannot; but this we can say, that, if there is such an element and if it is really responsible for all the protean manifestations of life, wonderful as radium and its doings are, they must sink into nothingness beside those of this new and unsuspected entity. The author evidently does not think that this path is a profitable one to pursue, and we agree with him; so he turns his attention to the question of energy. Energy is the capacity for doing work. It is often, of course, latent, as, for example, in a cordite cartridge, which is a peaceful, harmless thing until the energy stored up in it is realised with the accompanying explosion and work is done. It is the same with a bent spring; a clock-weight when the clock is not going, and so on. We need not develop this matter further; but one point must be alluded to, namely, the gradual exhaustion of the available energy in the changes from one manifestation to another. In all physical processes heat is evolved, which heat is distributed by conduction and radiation and tends to become universally diffused throughout space. When complete uniformity has been attained, all physical phenomena will come to an end; in other words, our solar system must come to an end, and it must have had a beginning. It is a well-known argument. Is there anything to rewind the clock which is running down before our very eyes? It was once urged that stellar collisions, and such-like things, might permit us to postulate a cyclical arrangement (and thus rearrangement) of universal phenomena; but that hypothesis does not seem to find any supporters to-day.