Page:Popular Science Monthly Volume 28.djvu/260

250 that Professor Huxley seems to recognize this view, or rather he regards the principle as one the truth of which is not proved, but which is valuable as a working hypothesis, and all the more valuable because it has never yet failed him. The separation of the principle from theological considerations is, however, practically impossible; we must make up our minds to many a fight upon the frontiers of the natural and the supernatural. Not a few persons believe that the possibility of religious faith, at this epoch of history, depends much upon the conclusions to which they come concerning the laws and operations of Nature; and I will not venture to deny that they who so believe have some reason to give for their belief.

It is in accordance with the statement just now advanced with regard to the close practical connection between the principle of the uniformity of Nature and theology that we find the said principle brought at once to the front in the Bishop of London's recent "Bampton Lectures," entitled "The Relations between Religion and Science." With the general argument and results of these undoubtedly able lectures I shall not here be concerned, but it will be much to my purpose to make a few observations upon what is said in the first of the series concerning the uniformity of Nature.

The earliest occasion upon which the phrase appears is to be found in the following sentence: "It will be admitted that the Supreme Postulate, without which scientific knowledge is impossible, is the Uniformity of Nature."

Now, a postulate is a proposition which is granted as the basis of an argument, because its truth is conceived to be self-evident; or at all events it is the simplest proposition to which a chain of reasoning can be reduced, and, if it be not granted, all further argument is impossible. Thus, Euclid's first postulate is, that from one point a straight line can be drawn to any other point. But surely it can scarcely be said of the uniformity of Nature that it has anything of this simple and self-evidencing character. The question, moreover, is not whether scientific knowledge be possible or impossible without it; if impossible, so much the worse for scientific knowledge. The question still recurs. Is the principle true? Moreover, can it be averred that scientific knowledge is impossible without this postulate? If so, why is it that the principle is not asserted in Newton's "Principia," or Laplace's "Mécanique Cèleste," or the various treatises on light, heat, electricity, botany, and what not? Certainly it seems to me extremely doubtful whether the "Supreme Postulate" either is admitted, or ought to be admitted, as the basis of scientific knowledge.

I suspect, however, that the bishop does not intend the word Postulate to be taken in its strict scientific sense; for he illustrates his position by reference to the discovery of the planet Neptune, which resulted from the assumption that the law of gravitation holds