Slowly he has been led on into a larger understanding of this wonderful universe. And what has he learned under this tuition? What are some of the great truths which have gradually impressed themselves upon his mind?
He has been made sure, for one thing, that this is a universe; that all its forces are coherent; that the same laws are in operation in every part of it. The principles of mathematics are everywhere applicable; gravitation controls all the worlds and every particle of matter in every one of them, and the spectroscope assures us that the same chemical elements which constitute our world are found in the farthest star. “On every hand,” says Walker, “we are assured that the guiding principle of Science is that of the uniformity of nature.”
It has also come to be understood that nature is all intelligible. Everything can be explained. This is the fundamental assumption of science. Many things have not yet been explained, but there is an explanation for everything; of that every thinker feels perfectly sure. “Fifty years ago,” says Sir John Lubbock, “the Book of Nature was like some richly illuminated missal, written in an unknown tongue; of the true meaning little was known to us; indeed we scarcely realized that there was a meaning to decipher. Now glimpses of the truth are gradually revealing themselves; we perceive that there is a reason—and in many cases we know what that reason is—for every difference in form, in size, and in color, for every bone and feather, almost for every hair."[6]
This is the latest word of the latest philosophy; there is a reason for everything. As Romanes says, Nature is instinct with reason; “tap her where you will, reason oozes out at every pore.”
If all things are rational and intelligible, then all things must be the product of a rational Intelligence. That conclusion seems inevitable.
But we can go further than this. It is not merely true that we can find in the world about us the signs of an Intelligence like our own, it is also true that our own intelligence has been developed by the revelation to us of this Intelligence in the world about us. “If,” says Walker, “human reason is but ’the reflection in us of the universe outside of us,’ then, clearly, the Reason was there, expressed in the universe, before it possibly could be reflected in us. It is our relation to the Universe that makes us rational.” And again, “Apart from the Reason expressed in the Universe around him, man could never have become the rational being that he is."[7]