It would be peculiarly interesting to examine further this principle of a practical, truly realistic experience ensured to human life through the inner [p.147] conflicts of experience. The history of morals and ethics, for example, notably of the perennial conflict between hedonism and idealism, could not but cast a good deal of light upon it; and the history of political struggles, or the history of the great controversies in science--such as that between vitalism and anti-vitalism or that between atomism and energism; or in philosophy, between dualism and monism; or in theology, between naturalism and supernaturalism, would also be most illuminating; while, also perhaps appealing only to the few, in the logic of the negative, as it has developed from the earliest times, or in psychological theory--for example, in the dispute of the advocates of the innervation theory and the afferent theory, or in Hering's theory of vision, or, again, in the life and movement of any one of the time-worn paradoxes of popular or scientific or philosophical ideas, one might expect to find suggestive illustration. In philosophy, Anaximander, Heraclitus, Zeno, Socrates, Spinoza, Kant, and Hegel have all found negation, or contradiction, necessary to any adequate account of reality. Explorations, however, in their teachings or along any of the paths that were suggested, would lead us too far astray. Fifthly, then, not only do the contradictions make experience realistic and so practical, but also they make it essentially social. A life or an experience that is contradictory has (1) movement, (2) unity or integrity, (3) reality and poise, and (4) practicality; and then it has besides, as if the medium through which these four things are sustained, (5) social character, society being only the visible expression, the [p.148] outer realization, of the both-sidedness, of the infinitely differential unity or the divided labour, which an active, yet thoroughly self-controlled, truly realistic, practical experience requires. In a former chapter, it will be readily recalled, an impulse to social life was found to be intimately connected with the attitude of doubt, and here clearly we are confronted with only another view of the same fact, since contradiction has become our most cogent reason for doubt and is now seen to require the social relations. An individual whose experience is ever divided against itself is, _ipso facto_, a social character, his social environment, whether in its narrowest or broadest manifestation, adding nothing to his nature or to the struggles of that nature, but only making the division against himself constantly and manifestly real. The social environment, as it were, just proves the man, his struggle and all, to himself. Some have agreed that the individual consciousness contained nothing on which to ground a positive case for society, for direct positive social interest; but so long as