Reference has been made in some fulness to Mr. Wallace's limitations of the theory of natural selection in the case of man's mental faculties. We must now pursue this somewhat in detail, reminding the reader of Mr. Wallace's admission that, "provisionally, the laws of variation and natural selection ... may have brought about, first, that perfection of bodily structure in which man is so far above all other animals, and, in co-ordination with it, the larger and more developed brain by means of which he has been able to subject the whole animal and vegetable kingdoms to his service." But, although Mr. Wallace rejects the theory of man's special creation as "being entirely unsupported by facts, as well as in the highest degree improbable," he contends that it does not necessarily follow that "his mental nature, even though developed _pari passu_ with his physical structure, has been developed by the same agencies." Then, by the introduction of a physical analogy which is no analogy at all, he suggests that the agent by which man was upraised into a kingdom apart bears like relation to natural selection as the glacial epoch bears to the ordinary agents of denudation and other changes in producing new effects which, though continuous with preceding effects, were not due to the same causes. Applying this "argument" (drawn from natural causes), as Mr. Wallace names it, "to the case of man's intellectual and moral nature," he contends that such special faculties as the mathematical, musical, and artistic (is this faculty to be denied the nest-decorating bower bird?), and the high moral qualities which have given the martyr his constancy, the patriot his devotion, and the philanthropist his unselfishness, are due to a "spiritual essence or nature, superadded to the animal nature of man." We are not told at what stage in man's development this was inserted; whether, once and for all, in "primitive" man, with potentiality of transmission through Palæolithic folk to all succeeding generations; or whether there is special infusion of a "spiritual essence" into every human being at birth. Any perplexity that might arise at the line thus taken by Mr. Wallace vanishes before the fact, already enlarged upon, that the author of the Malay Archipelago and Island Life has written a book on Miracles and Modern Spiritualism in defence of both. The explanation lies in that duality of mind which, in one compartment, ranks Mr. Wallace foremost among naturalists, and, in the other compartment, places him among the most credulous of Spiritualists. Despite this, Mr. Wallace has claims to a respectful hearing and to serious reply. Fortunately, he would appear to furnish the refutation to his own argument in the following paragraph from his delightful Contributions to the Theory of Natural Selection: