Exactly; it is quite probable. It is, in fact, improbable that man is the highest type of existence. But if Professor Haeckel is ready to grant that probability or even possibility, why does he so strenuously exclude the idea of revelation, _i.e._, the acquiring of imparted information from higher sources? Savages can certainly have "revelation" from civilised men. Why, then, should it be inconceivable that human beings should receive information from beings in the universe higher than themselves? It may or may not be the case that they do; but there is no scientific ground for dogmatism on the subject, nor any reason for asserting the inconceivability of such a thing. Professor Haeckel would no doubt reply to some of the above criticism that he is not only a man of science, but also a philosopher, that he is looking ahead, beyond ascertained fact, and that it is his philosophic views which are in question rather than his scientific statements. To some extent it is both, as has been seen; but if even the above be widely known—if it be generally understood that the most controversial portions of his work are mainly speculative and hypothetical, it can be left to its proper purpose of doing good rather than harm. It can only do harm by misleading, it can do considerable good by criticising and stimulating and informing; and it is an interesting fact that a man so well acquainted with biology as Professor Haeckel is should have been so strongly impressed with the truth of some aspect of the philosophic system known as Monism. Many men of science have likewise been impressed with the probability, or possibility, of some such ultimate unification. The problem to be solved—and an old-world problem indeed it is—is the range, and especially the nature, of the connection between mind and matter; or, let us say, between the material universe on the one hand, and the vital, the mental, the conscious and spiritual universe or universes, on the other.