idealism of Berkeley, as we have no logical right to deny or to affirm the existence of absolute matter or of absolute mind.  The real truth of the philosophy of science lies in a separation between metaphysical theory and actual pursuits.  In ultimate philosophical theory it is impossible to rest content with a plain natural conception of the universe.  When any conception of matter, or of its affections, is pushed as far as analysis can take us, what we know resolves itself into affections of mind, into what without metaphysical finesse may be called ideas.  But this empirical idealism must be taken positively as being merely the limits of our knowledge, and it must carry with it neither an undue exaltation of mind nor an undue depreciation of matter.

“The Platonic philosophy is probably the grandest example of the unscientific use of the imagination extant; and it would be hard to estimate the amount of detriment to clear thinking effected, directly and indirectly, by the theory of ideas, on the one hand, and by the unfortunate doctrine of the baseness of matter, on the other.”

Materialism was dismissed by Huxley as being an inadequate philosophical explanation of the universe, and as being based on a logical delusion.  There remains, however, a practical application of the word in which the conceptions it involves are almost an inevitable part of science, and which was strenuously urged by Huxley.  In the earlier days of the world and of science almost all the phenomena of nature were regarded as random or wilful displays of living intelligence.  The earth itself and the sun, the moon, and the stars were endowed with life; legions of unseen intelligences ruled the operations of nature, and although these might be bribed or threatened, pleased or made angry, their actions were regarded as beyond prediction or control.  The procession of the seasons, the routine of day and night, the placid appeasement of the rains, the devastating roar of storms, the shining of the rainbow, the bubbling of springs, the terrors of famine and pestilence; all these—­the varying environment which makes or mars human life—­were regarded as inevitable and capricious.  The whole progress of physical science has been attended with a gradual elimination of these supernatural agencies and with a continual replacement of them by conceptions of physical sequence.

“In singular contrast with natural knowledge, the acquaintance of mankind with the supernatural appears the more exact, and the influence of supernatural doctrine on conduct the greater, the further we go back in time and the lower the stage of civilisation submitted to investigation.  Historically, indeed, there would seem to be an inverse relation between supernatural and natural knowledge.  As the latter has widened, gained in precision and trustworthiness, so has the former shrunk, grown vague and questionable; as the one has more and more filled the sphere