[69:1] For a clear brief summary of the theory the reader may be referred to a little work by Sir William Ramsay, F.R.S., entitled Elements and Electrons, pp. 8-15.
IV
THE DOCTRINE OF ENERGY[81:1]
The problem of Metaphysics—the nature of Reality—still presses for a solution. Agnosticism is but a cautious idealism—a timid phenomenalism. That philosophy, however named, which proclaims that the experience of life is nothing more than a vain show, a pantomime of sensations distinguished only from ideas by their greater intensity and distinctness, is not only a confession of failure. It is a denial of fact.
To know the nature of the Absolute as such, to present the Absolute to finite minds as it must be presented, if that be possible, to the Absolute itself, must ever remain impossible to man. But it is equally true that to attempt such a task has never been the urgent mission of Philosophy. The distinction between the Ideal and the Real, between the conceptual and the perceptual, is quite certainly and incessantly recognised. Agnosticism can neither deny the fact successfully, nor solve the speculative difficulties which its recognition raises up. The Real and the Ideal, essentially distinct yet mockingly similar, for ever blend and intermingle in the composite experience of life. Truly to discriminate and unravel these,—validly to separate the Ideal element which impregnates that Reality which we are for ever compelled to postulate and recognise, still remains the great problem of Philosophy—humbler perhaps and more practical, but not less profound than any vain attempt to discover to finite conception the Absolute as it is in itself. Therefore it is that the efforts of negative and agnostic criticism to dispense with the recognition of Reality as a necessary postulate of our activity are foredoomed to failure. They leave us not a solitude which we might pretend to be peace, but a seething sea of troubles urgently demanding a new attempt to reveal the unity which must underlie the infinite diversity of experience.
Such, indeed, seems to us the present position of Metaphysics; and, what is more important, it appears to react with increasing force upon the theories and investigations of Science.
The problem of Reality is thus at present not without a special and increasing interest for the students of Physical Science. Until lately they have been taught and have always maintained that Matter is the direct object of sense-perception. No doubt it is long since Philosophy has urged that our conceptions of the external world are a mentally constructed system. But this doctrine has made but little impression upon the students of Natural Science. The objective origin of our sensations and the apparently objective reality also of the intelligible qualities and operative laws of the external world are too strongly impressed upon their minds. Idealism and Transcendentalism have carried no conviction to them. Still, the difficulties of common sense have continued to grow. Recent developments of scientific theory have increased the urgency of the problem, but they seem to us also to suggest a solution the beneficial results of which affect the whole of Metaphysics.
We refer to the doctrine of Energy, which occupies now as great a place in the physical sciences as the doctrine of Evolution does in the zoological sciences.