Just as "caloric" no longer serves and is no longer possible as the supposed "explanation" of the behaviour of bodies in the hot or the cold state, so we no longer require the supposition of "spirits" of one kind or another as "explanations" of the living state of those products of our mother earth which are called plants, animals and men. In neither case do such "spirits" really "explain" the state in question; they are only names for the activity which it was imagined that they served to explain. These states or affections of matter remain as wonderful and important to us as they were before. But by giving up the prehistoric notions about them which have been handed on until the present day we can think of them in a more satisfactory way--a way which avoids the multiplication of unnecessary imaginary agencies and the conception of an intermittent and hesitating Creative Power, and substitutes for it the operation of continuous orderly and preordained forces. It is true that we can neither ascertain nor imagine either the beginning or the end of the orderly process which we discover in operation to-day. We can trace it back by well-established inference into a remote past, but a beginning of it is not within the possibilities of human thought. We can, with reasonable probability of being correct, foretell the changes and developments which time will bring in many combinations and dispositions which are the manifestations of that process at this moment of time, but we cannot even think of a cessation of that process. Should we ask, "Why does this process exist?" there is no answer. Nature does not reply; an awful silence meets our inquiry. The reproach is often urged against science--the knowledge of the order of nature--that it does not tell us "why we are here." Man inevitably desires to know why he is here; but "science," as that word is now understood, does not profess or even seek to answer that question, although the false hope has been raised in ignorant minds, sometimes by knavery, sometimes by honest delusion, that it could do so. By knowledge of nature mankind can escape much suffering and gain the highest happiness, but that is all that we can hope for from it. We shall never satisfy our curiosity; we shall never know in the same way as we know the order of nature, why--to what end, for what purpose--that order and not another order exists.