Page:Chesterton - Eugenics and Other Evils (Cassell, 1922).djvu/78

 give the best definition and history of the words "geography" and "geology."

Now the students of heredity, especially, understand all of their subject except their subject. They were, I suppose, bred and born in that brier-patch, and have really explored it without coming to the end of it. That is, they have studied everything but the question of what they are studying. Now I do not propose to rely merely on myself to tell them what they are studying. I propose, as will be seen in a moment, to call the testimony of a great man who has himself studied it. But to begin with, the domain of heredity (for those who see its frontiers) is a sort of triangle, enclosed on its three sides by three facts. The first is that heredity undoubtedly exists, or there would be no such thing as a family likeness, and every marriage might suddenly produce a small negro. The second is that even simple heredity can never be simple; its complexity must be literally unfathomable, for in that field fight unthinkable millions. But yet again it never is simple heredity: for the instant anyone is, he experiences. The third is that these innumerable ancient influences, these instant inundations of experiences, come together according to a combination that is unlike anything else on this earth. It is a combination that does combine. It cannot be sorted out again, even on the Day of Judgment. Two totally different people have become in the sense most sacred, frightful, and unanswerable, one flesh. If a