SOME PROBLEMS OF CONCEPTION. 153 ciple of its differences". 1 With the General Equation it is quite another matter. The sum of its coefficients must have a definite value, and this must either be zero or some quantity with positive or negative sign. Hence the number and nature of the alternative modifications are deducible from the general conception itself when taken in conjunction with certain general axioms concerning quantity in fact as Aristotle would put it from the ISia apxrf* which defines the 7i>o9 in conjunction with certain KOIVO, a^Lw^ara of wider application. 2 The deduction is not indeed always as simple as this. An animal must respire, and must therefore have some specific method of respiration. But there are no assignable elements in the conception of animal organisation, from which we could infer that the methods of respiration must be such as we find and no more. We might doubtless say a priori^ that respiration must either take place through a special organ or through the undifferentiated surface of the body. But beyond this we could not go, even, as recent investiga- tion tends to show, by bringing the laws of osmosis in to our assistance. And this is no mere accident of incomplete knowledge. On the contrary, all we know of organic evolu- tion would go to prove that the form of the respiratory system will depend as much on the environment as on the organism itself, and that with a modified environment a different method of breathing would be possible. In such a case the general conception contains the germ rather than the principle of its different forms, and the development of the germ will depend in part on considerations which we must regard as external. The mention of the ' germ ' recalls another point on which a few words may be said. We spoke above of the element of identity as a mere abstraction, but there may perhaps be cases in which the element or tendency which appears in many varying forms should also be allowed a certain reality upon its own account. It seems to be so, for example, with ethical ends. Thus we might define the Socialistic spirit as the attempt to extend the principles and conduct which are realised with tolerable success in the family to the state at 1 Cf. Hegel, op. cit., p. 47. 2 Of course we may so define any given curve as to make it quite as definite as a square. And such a curve would be realised in a variety of ways which would be quite irrelevant to it. Conversely the square itself may be treated as a specific case of a higher ' organic ' concept. The distinction is between the relations of each concept to the cases coming immediately under it. See below, V.
