We can no longer separate things as we once could: everything tends towards unity; one thing, one action, in one place, at one time. On the other hand, we can no longer unify things as we once could; we are driven to ultimate atoms, each one of which is an individuality. So that we have an infinite multitude of things doing an infinite multitude of actions in infinite time and space; and yet they are not many things, but one thing. The Atom The idea of an indivisible, ultimate atom is inconceivable by the lay mind. If we can conceive an idea of the atom at all, we can conceive it as capable of being cut in half indeed, we cannot conceive it at all unless we so conceive it. The only true atom, the only thing which we cannot subdivide and cut in half, is the universe. We cannot cut a bit off the universe and put it somewhere else. Therefore, the universe is a true atom and, indeed, is the smallest piece of indivisible matter which our minds can conceive; and they cannot conceive it any more than they can the indivisible, ultimate atom. Our Cells A string of young ducklings as they sidle along through grass beside a ditch—how like they are to a single serpent! I said in _Life and Habit_ that a colossal being, looking at the earth through a microscope, would probably think the ants and flies of one year the same as those of the preceding year. I should have added:—So we think we are composed of the same cells from year to year, whereas in truth the cells are a succession of generations. The most continuous, homogeneous things we know are only like a lot of cow-bells on an alpine pasture. Nerves and Postmen A letter, so long as it is connected with one set of nerves, is one thing; loose it from connection with those nerves—open your fingers and drop it in the opening of a pillar box—and it becomes part and parcel of another nervous system. Letters in transitu contain all manner of varied stimuli and shocks, yet to the postman, who is the nerve that conveys them, they are all alike, except as regards mere size and weight. I should think, therefore, that our nerves and ganglia really see no difference in the stimuli that they convey. And yet the postman does see some difference: he knows a business letter from a valentine at a glance and practice teaches him to know much else which escapes ourselves. Who, then, shall say what the nerves and ganglia know and what they do not know? True, to us, as we think of a piece of brain inside our own heads, it seems as absurd to consider that it knows anything at all as it seems to consider that a hen’s egg knows anything; but then if the brain could see us, perhaps the brain might say it was absurd to suppose that that thing could know this or that. Besides what is the self of which we say that we are self-conscious? No one can say what it is that we are conscious of. This is one of the things which lie altogether outside the sphere of words.