We see therefore that as between the teaching of Pythagoras and that of Prof. Aitken there is a great gulf fixed. It will probably be bridged by a little freer use of the scientific imagination that Prof. Huxley extolled. The great American astronomer has argued humanity out of existence in a manner so complete as to warrant the instant dismantling of the statue of Bruno by the Vatican. But alas for the shortcomings of dogmatic science, we have not yet been told how or why the Earth alone is favoured by the presence of humanity. We are left to speculate upon the question as to what has become of the Moon’s humanity, supposing this dead orb was once alive and afforded habitable conditions. We are left wondering why conservative Nature evolved the planets Neptune and Uranus—which “are so far away from the Sun that its light and heat can hardly be effective in protecting life upon them, even should life in any way originate there”—if they are never to come within the life-belt limit of the solar rays! These vapourings are altogether unworthy of the name of Science, and are, in their way, as fanciful and speculative as any of the superstitions of a primitive religion. Who gave the astronomer to know that man as we see him is the only sort of humanity or intelligent being that can exist? It is open to him to remark that even should there be forms of intelligent life on other planets we should not recognize them as human. That is beside the mark; we do not recognize the human by its form, we do not confound the man with the animal part of him; and we may even speak of discarnate humanity. In every possible way we protest that articulate language, which infers articulate thought and intelligence, is the criterion of the human, and in this category we include for sociological reasons all that are of human generation, whether intelligent and articulate or not. Of the “infinite variability” of God as expressed in Nature, the astronomer takes no count. Here on this globe of ours we find the human persisting in temperatures varying from over + 150° to - 30°, and we have no reason for suggesting that the power of adaptation to environment is at the maximum in this world. Violent ophthalmia and even madness would result in us if “the earth’s green livery” were suddenly and permanently changed to red. But a very little alteration in the chemical constitution of the vitreous fluid in the eye would render us immune from these evils, and we have every reason for thinking that were such a colour-change to take place, Nature would not be long in adapting herself to the new conditions. But she would first be sure that they were likely to be permanent, for although very amicable, the old lady is extremely cautious and prudent! What we know as solar light and heat have no existence outside the earth’s atmosphere, and even within it they only have the values that our sensation-consciousness gives to them; so that all we can scientifically assume in regard to those