So far, we have spoken as if the Socratic definitions were merely verbal; they were, however, a great deal more, and their author did not accurately discriminate between what at that stage of thought could not well be kept apart—explanations of words, practical reforms, and scientific generalisations. For example, in defining a ruler to be one who knew more than other men, he was departing from the common usages of language, and showing not what was, but what ought to be true.[93] And in defining virtue as wisdom, he was putting forward a new theory of his own, instead of formulating the received connotation of a term. Still, after making every deduction, we cannot fail to perceive what an immense service was rendered to exact thought by introducing definitions of every kind into that department of enquiry where they were chiefly needed. We may observe also that a general law of Greek intelligence was here realising itself in a new direction. The need of accurate determination had always been felt, but hitherto it had worked under the more elementary forms of time, space, and causality, or, to employ the higher generalisation of modern psychology, under the form of contiguous association. The earlier cosmologies were all processes of circumscription; they were attempts to fix the limits of the universe, and, accordingly, that element which was supposed to surround the others was also conceived as their producing cause, or else (in the theory of Heracleitus) as typifying the rationale of their continuous transformation. For this reason Parmenides, when he identified existence with extension, found himself obliged to declare that extension was necessarily limited. Of all the physical thinkers, Anaxagoras, who immediately precedes Socrates, approaches, on the objective side, most nearly to his standpoint. For the governing Nous brings order out of chaos by segregating the confused elements, by separating the unlike and drawing the like together, which is precisely what definition does for our conceptions. Meanwhile Greek literature had been performing the same task in a more restricted province, first fixing events according to their geographical and historical positions, then assigning to each its proper cause, then, as Thucydides does, isolating the most important groups of events from their external connexions, and analysing the causes of complex changes into different classes of antecedents. The final revolution effected by Socrates was to substitute arrangement by difference and resemblance for arrangement by contiguity in coexistence and succession. To say that by so doing he created science is inexact, for science requires to consider nature under every aspect, including those which he systematically neglected; but we may say that he introduced the method which is most particularly applicable to mental phenomena, the method of ideal analysis, classification, and reasoning. For, be it observed