of a single element, cannot possibly be taken as a warrant for so huge an inference as that there are really more than sixty elements all endowed with absolutely distinctive properties by a supernatural cause. Now this consideration, which arises immediately from the doctrine of the relativity of knowledge, is alone amply sufficient to destroy the present argument. But we must not on this account lose sight of the fact that, even to our strictly relative science in its present embryonic condition, we are not without decided indications, not only that the so-called elements are probably for the most part compounds, but even that matter as a whole is one substance, which is itself probably but some modification of energy. Indeed, the whole tendency of recent scientific speculation is towards the view that the universe consists of some one substance, which, whether self-existing or created, is diverse only in its relation to ignorance. And if this view is correct, how obvious is the inference which I have elaborated in Sec. 32, that all the diverse forms of matter, as we know them, were probably evolved by natural causes. So obvious, indeed, is this inference, that to resort to any supernatural hypothesis to explain the diverse properties of the various chemical elements appears to me a most glaring violation of the law of parcimony--as much more glaring, for instance, than the violation of this law by Paley, as the number and variety of organic species are greater than the number and variety of chemical species. And if it was illegitimate in Paley to use a mere absence of knowledge as to how the transmutation of apparently fixed species of animals was effected as equivalent to the possession of knowledge that such transmutation had not been effected, how much more illegitimate must it be to commit a similar sin against logic in the case of the chemical elements, where our classification is confessedly beset with numberless difficulties, and when we begin to discern that in all probability it is a classification essentially artificial. Lastly, the mere fact that the transmutation of chemical species and the evolution of chemical "atoms" are processes which we do not now observe as occurring in nature, is surely a consideration of a far more feeble kind than it is even in the case of biological species and biological evolution; seeing that nature's laboratory must be now so inconceivably different from what it was during the condensation of the nebula. What an atrocious piece of arrogance, therefore, it is to assert that "none of the processes of nature, _since the time when nature began_, have produced the slightest difference in the properties of any molecule!" No one can entertain a higher respect for Professor Clark Maxwell than I do; but a single sentence of such a kind as this cannot leave two opinions in any impartial mind concerning his competency to deal with such subjects.