individual trees present varying degrees of slope according to their position. The total experience of these two clumps of sycamores and of any two in each clump is obviously different. In a windy situation you can tell in July which is the prevailing wind by noting the main inclination of the ears of corn in a field. Again two male sticklebacks in a pond will make nests for the eggs, there to be deposited, and one will choose a spot on the southern and another on the northern side of a little promontory of soil and stones at the edge of the pond. One will find ready for him materials for building his nest different from those of his rival, and he and his wife and family will receive for that season very different stimuli, and so will the stimuli differ in other phases of their existence in a pond occupying a few square yards. On a sandy bank in a garden facing south you may discover two little caves ingeniously hidden by a small opening, and in each of them you can see a toad. Though these are only a few feet apart one is more widely open to sun and wind than the other and one deeper than the other, and whatever the other activities of the two toads may be in their little shelters, they receive stimuli different in strength and number. On another bank in the same garden less exposed to view, and altogether more sheltered from sun and wind and enemies, a robin has built a well-hidden nest. If the six fledglings in the nest are watched when the mother is absent they are seen to occupy very different positions of comfort, pressure and warmth. When the mother-bird returns from marketing she is hardly impartial in the amount of food she puts into their open beaks. But the slight and perhaps unimportant inequality of their experiences as fledglings is nothing to that which follows when they fly abroad, and which continues to the end of their lives, the life of a robin being somewhere about ten years long. The differences of the _total experience_ of the six young robins is easy to picture. Again, surely, the total experience of two fleas on the body of one plague-rat must be for such small creatures of importance to their welfare, according as their respective “pitches” are on the abdomen, back or legs of the host. When the life-history of a human being is told in full the discontinuity of his total experience needs no proof. The proof is written large before our eyes. But, perhaps, one example may be given. There are two very eminent living writers, whose light has certainly for some years not been hidden under a bushel, Mr. Chesterton and Mr. George Bernard Shaw. We may be said to know them well. Leaving out of sight the Celtic strain claimed by one, and indeed all inherited differences, we see two men of perhaps equal ability, near of an age, both living in London, both living by their pen, both in easy circumstances. When one considers for a moment the different company these two men keep, their different and opposing outlook on