I must not be understood as ignoring the fact that this lower species of theism has been entertained by some of the loftiest minds of our race, both in ancient and in modern times. When once such an ever-present conception as the idea of God has become intertwined with the whole body of the thoughts of mankind, it is very difficult for the most powerful and subtle intelligence to change the form it has taken. It has become so far organized into the texture of the mind that it abides there unconsciously, like our fundamental axioms about number and magnitude; it sways our thought hither and thither without our knowing it. The two forms of theism here contrasted have slowly grown up under the myriad unassignable influences that in antiquity caused nature-worship to predominate among some people and ancestor-worship among others; they have coloured all the philosophizing that has been done for more than twenty centuries; and it is seldom that a thinker educated under the one form ever comes to adopt the other and habitually employ it, save under the mighty influence of modern science, the tendency of which, as we shall presently see, is all in one direction.
Among ancient thinkers the view of Deity as remote from the world prevailed with the followers of Epikuros, who held that the immortal gods could not be supposed to trouble themselves about the paltry affairs of men, but lived a blessed life of their own, undisturbed in the far-off empyrean. This left the world quite under the sway of blind forces, and thus we find it depicted in the marvellous poem of Lucretius, one of the loftiest monuments of Latin genius. It is to all appearance an atheistic world, albeit the author was perhaps more profoundly religious in spirit than any other Roman that ever lived, save Augustine; yet to his immediate scientific purpose this atheism was no drawback. When we are investigating natural phenomena, with intent to explain them scientifically, our proper task is simply to ascertain the physical conditions under which they occur, and the less we meddle with metaphysics or theology the better. As Laplace said, the mathematician, in solving his equations, does not need "the hypothesis of God."[13] To the scientific investigator, as such, the forces of nature are doubtless blind, like the _x_ and _y_ in algebra, but this is only so long as he contents himself with describing their modes of operation; when he undertakes to explain them philosophically, as we shall see, he can in no wise dispense with his theistic hypothesis. The Lucretian philosophy, therefore, admirable as a scientific coördination of such facts about the physical universe as were then known, goes but very little way as a philosophy. It is interesting to note that this atheism followed directly from that species of theism which placed God outside of his universe. We shall find the case of modern atheism to be quite similar. As soon as this crude and misleading conception of God is refuted, as the whole progress of scientific knowledge tends to refute it, the modern atheist or positivist falls back upon his universe of blind forces and contents himself with it, while zealously shouting from the housetops that this is the whole story.