Now, there is a striking law over which few people seem to have pondered. It is this: That among all the differences which exist, the only ones that interest us strongly are those _we do not take for granted_. We are not a bit elated that our friend should have two hands and the power of speech, and should practise the matter-of-course human virtues; and quite as little are we vexed that our dog goes on all fours and fails to understand our conversation. Expecting no more from the latter companion, and no less from the former, we get what we expect and are satisfied. We never think of communing with the dog by discourse of philosophy, or with the friend by head-scratching or the throwing of crusts to be snapped at. But if either dog or friend fall above or below the expected standard, they arouse the most lively emotion. On our brother's vices or genius we never weary of descanting; to his bipedism or his hairless skin we do not consecrate a thought. _What_ he says may transport us; that he is able to speak at all leaves us stone cold. The reason of all this is that his virtues and vices and utterances might, compatibly with the current range of variation in our tribe, be just the opposites of what they are, while his zoölogically human attributes cannot possibly go astray. There {258} is thus a zone of insecurity in human affairs in which all the dramatic interest lies; the rest belongs to the dead machinery of the stage. This is the formative zone, the part not yet ingrained into the race's average, not yet a typical, hereditary, and constant factor of the social community in which it occurs. It is like the soft layer beneath the bark of the tree in which all the year's growth is going on. Life has abandoned the mighty trunk inside, which stands inert and belongs almost to the inorganic world. Layer after layer of human perfection separates me from the central Africans who pursued Stanley with cries of "meat, meat!" This vast difference ought, on Mr. Allen's principles, to rivet my attention far more than the petty one which obtains between two such birds of a feather as Mr. Allen and myself. Yet while I never feel proud that the sight of a passer-by awakens in me no cannibalistic waterings of the mouth, I am free to confess that I shall feel very proud if I do not publicly appear inferior to Mr. Allen in the conduct of this momentous debate. To me as a teacher the intellectual gap between my ablest and my dullest student counts for infinitely more than that between the latter and the amphioxus: indeed, I never thought of the latter chasm till this moment. Will Mr. Allen seriously say that this is all human folly, and tweedledum and tweedledee?