as saying in point—"I had thought the same parts of the same species more resemble (than they do anyhow in Cirripedia) objects cast in the same mould. Systematic work would be easy, were it not for this confounded variation which, however, is pleasant to me as a speculatist, though odious to me as a systematist."[1]
It is to Darwin's everlasting glory that he overcame this seeming opposition, and gave the world an object lesson in true logical procedure, by constructing a working system which was capable of rationalizing his facts, and yet at the same time sufficiently elastic to modify its own lines so as to comprehend new varieties and seeming exceptions. Darwin was essentially a system maker; but his system was made for facts, and not facts for his system. As a corollary to this conception of the relation of systematic knowledge to the variable instances which it comprehends, there is the problem of the reconciliation of the contradictories which experience exhibits, and which it is alleged our logical concepts are incapable of interpreting. Here again it is only an artificial view of logic which regards its concepts as set with an iron rigidity.
Professor James insists that "for conceptual logic the same is nothing but the same."[2] This bare statement of the law of identity modern logic repudiates most emphatically. The essential nature of the concept is that it represents unity in the midst of difference, identity in variety; and this is richly illustrated in those great constructive concepts of science whose characteristic feature has been the effort to confine in one idea the reciprocal action of opposed forces. Such are the concepts of action and reaction, attraction and repulsion, stress and strain, positive and negative electricity, north and south poles of the magnetic field, endosmosis and exosmosis, anabolism and catabolism. All of these express a synthesis of opposed elements. And in the light of concepts such as these, it is absurd to declare that the essential nature of concepts is that of rigid exclusion and unrelated isolation.
If our intellect is incapable of aiding us in the interpretation of
