Thus far the remarks which I have made apply equally to all forms of Religion, as such, whether actual or possible, and in so far as the Religion is _pure_. But it is notorious that until quite recently Religion did exercise upon Science, not only an influence, but an overpowering influence. Belief in divine agency being all but universal, while the methods of scientific research had not as yet been distinctly formulated, it was in previous generations the usual habit of mind to refer any natural phenomenon, the physical causation of which had not been ascertained, to the more or less immediate causal action of the Deity. But we now see that this habit of mind arose from a failure to distinguish between the essentially distinct characters of Science and Religion as departments of thought, and therefore that it was only so far as the Religion of former times was impure--or mixed with the ingredients of thought which belong to Science--that the baleful influence in question was exerted. The gradual, successive, and now all but total abolition of final causes from the thoughts of scientific men, to which allusion has already been made, is merely an expression of the fact that scientific men as a body have come fully to recognize the fundamental distinction between Science and Religion which I have stated. Or, to put the matter in another way, scientific men as a body--and, indeed, all persons whose ideas on such matters are abreast of the times--perceive plainly enough that a religious explanation of any natural phenomenon is, from a scientific point of view, no explanation at all. For a religious explanation consists in referring the observed phenomenon to the First Cause--i.e. to merge that particular phenomenon in the general or final mystery of things. A scientific explanation, on the other hand, consists in referring the observed phenomenon to its physical causes, and in no case can such an explanation entertain the hypothesis of a final cause without abandoning its character as a scientific explanation. For example, if a child brings me a flower and asks why it has such a curious form, bright colour, sweet perfume, and so on, and if I answer, Because God made it so, I am not really answering the child's question: I am merely concealing my ignorance of Nature under a guise of piety, and excusing my indolence in the study of botany. It was the appreciation of this fact that led Mr. Darwin to observe in his _Origin of Species_ that the theory of creation does not serve to explain any of the facts with which it is concerned, but merely re-states these facts as they are observed to occur. That is to say, by thus merging the facts as observed into the final mystery of things, we are not even attempting to explain them in any scientific sense: for it would be obviously possible to get rid of the necessity of thus explaining any natural phenomenon whatsoever by referring it to the immediate causal action of the Deity.