Our second reason is as follows. Biology is once more the link between root and flower, between physics and chemistry and human affairs, in regard to evolution. I say evolution: it would be better to broaden the idea by saying the directional processes to be seen in the universe. So far as a main direction is to be observed in physics and chemistry, it is, as all authorities are agreed, towards the degradation of energy and a final state in which not only life but all activity whatsoever will be reduced to nothing, all the waters of energy run down into a single dead level of moveless ocean. Biology, on the other hand, presents us with the spectacle of an evolution in which the main direction is the raising of the maximum level of certain qualities of living beings, such as efficiency of organs, co-ordination, size, accuracy and range of senses, capacity for knowledge, memory and educability, emotional intensity,--qualities which in one way or another lead to a more efficient control by the organism over the external world, and to its greater independence. A direction towards more mind is visible; and this development of greater mental powers has been in all the later stages the chief instrument of acquiring control and independence. More and more of matter is embodied in living organisms, more and more becomes subservient to life. Thus, while in physics and chemistry we see a tendency towards the extinction of life and activity, in biology we see a tendency towards more life and more activity; and this latter tendency is accompanied and largely made possible by the evolution of greater intensity of mental process--of something, that is to say, of which we cannot as yet take account in physics and chemistry. The biologist may well ask himself the question--“Is it not possible that this evolving mind, of whose achievements on its new level in man we are only seeing the beginning, may continue to find more and more ways of subordinating the inorganic to itself, and that it may eventually retard or even prevent the attainment of this complete degradation of energy prophesied by physico-chemical science? Is it not possible that this great generalization only applies to phenomena in their purely material aspect, and that when we learn to detect and measure the mental aspects of phenomena we may find reason to modify the universal applicability of this law of degradation?” We do not know the answer to that question: but it is clearly a legitimate and useful question to ask. In any event, we constatate two chief directions in the universe; that seen in biology is in many ways opposed to that seen in physics and chemistry; and both must be taken into account.