With one who reasons thus we may certainly feel a sympathy. The most ardent advocate of mechanism must admit that his doctrine is a working hypothesis, and not _proved_ to be true. Its acceptance would, however, be a genuine convenience from the point of view of science, for it does introduce, at least provisionally, a certain order into a vast number of facts, and gives a direction to investigation. Perhaps the wisest thing to do is, not to combat the doctrine, but to accept it tentatively and to examine carefully what conclusions it may seem to carry with it--how it may affect our outlook upon the world as a whole. 45. THE PLACE OF MIND IN NATURE.--One of the very first questions which we think of asking when we contemplate the possibility that the physical world is throughout a mechanical system is this: How can we conceive minds to be related to such a system? That minds, and many minds, do exist, it is not reasonable to doubt. What shall we do with them? One must not misunderstand the mechanical view of things. When we use the word "machine," we call before our minds certain gross and relatively simple mechanisms constructed by man. Between such and a flower, a butterfly, and a human body, the difference is enormous. He who elects to bring the latter under the title of mechanism cannot mean that he discerns no difference between them and a steam engine or a printing press. He can only mean that he believes he might, could he attain to a glimpse into their infinite complexity, find an explanation of the physical changes which take place in them, by a reference to certain general laws which describe the behavior of material particles everywhere. And the man who, having extended his notion of mechanism, is inclined to overlook the fact that animals and men have minds, that thought and feeling, plan and purpose, have their place in the world, may justly be accused of a headlong and heedless enthusiasm. Whatever may be our opinion on the subject of the mechanism of nature, we have no right to minimize the significance of thought and feeling and will. Between that which has no mind and that which has a mind there is a difference which cannot be obliterated by bringing both under the concept of mechanism. It is a difference which furnishes the material for the sciences of psychology and ethics, and gives rise to a whole world of distinctions which find no place in the realm of the merely physical. There are, then, minds as well as bodies; what place shall we assign to these minds in the system of nature?