To begin with, such an analogy, dealing as it does with the relation of a part to the whole, has and should have, for a reason not hard to find, the freedom of the city of logic. Other than logical approval of it might be cited. Biology and sociology and psychology might be called in to give testimony. And out of the past, the more recent past at least as known to the historian of philosophy, Leibnitz with his _lex analogiæ_, or for that matter with the general import of his monadology, might be appealed to. But without tarrying for assistance from these quarters, highly respectable though they are, I make a simple, yet perhaps timely and--with apologies for so much emotion--soul-satisfying reference to the logic in the case, for after all biology and sociology and psychology are always under the restraints of logic, as well as alliterated with it; nor does the evidence of logic depend on mere technical acquaintance with given sets of facts. Thus, in these enlightened days, to say nothing of Plato's time or Aristotle's, how can the true part of anything ever dare [p.157] not to have an analogy, even a "part-for-part" or "one-to-one" correspondence to the whole in which it is comprised? And--this being, as in due time will appear, quite as important--how can a whole, be it society or nature or anything else, ever have parts without having also, actually or potentially, parts within its parts? In fact, given any divided whole, and the division, however far it may be carried, will always involve at least these three typical factors: (1) The individual as the part still undivided, though at the same time necessarily inwardly alive with the self-same differential operation to which it has owed its origin; (2) the group-part or class, which for the convenience of the adjective form may be known also as the faction, and which was so important to Plato in his analogy of the individual to a class-divided society; and (3) the all-inclusive whole. And among these factors in all possible ways--that is, even between individual and individual, or individual and group or group and group, as well as between either individual or group and whole--an analogy in terms of all the various elements of the original differential operation will persist. Such, almost truistically, though also perhaps somewhat subtly for ordinary purposes, is the logical condition of division or differentiation. Difference, like its limit opposition, is thus a great mixer, and division can be no mere separation or isolation of parts. The saying comes to my mind from somewhere, that though division may reveal distinct vertebræ, the vertebra always conceal a spinal cord.