IX. Conflict between analytical criticism and scholasticism, 426—The theory of evolution as a new application of the atomistic method, 427—Transitional character of the principal systems of the nineteenth century, 428—Aristotelian ideas in modern French thought, 428—Contrasting relations of ancient and modern philosophy to theology, 430. THE GREEK PHILOSOPHERS. CHAPTER I. THE STOICS. I. The systems of Plato and Aristotle were splendid digressions from the main line of ancient speculation rather than stages in its regular development. The philosophers who came after them went back to an earlier tradition, and the influence of the two greatest Hellenic masters, when it was felt at all, was felt almost entirely as a disturbing or deflecting force. The extraordinary reach of their principles could not, in truth, be appreciated until the organised experience of mankind had accumulated to an extent requiring the application of new rules for its comprehension and utilisation; and to make such an accumulation possible, nothing less was needed than the combined efforts of the whole western world. Such religious, educational, social, and political reforms as those contemplated in Plato’s _Republic_, though originally designed for a single city-community, could not be realised, even approximately, within a narrower field than that offered by the mediaeval church and the feudal state. The ideal theory first gained practical significance in connexion with the metaphysics of Christian theology. The place given by Plato to mathematics has only been fully justified by the development of modern science. So also, Aristotle’s criticism became of practical importance only when the dreams against which it was directed had embodied themselves in a fabric of oppressive superstition. Only the vast extension of reasoned knowledge has enabled us to disentangle the vitally important elements of Aristotle’s logic from the mass of useless refinements in which they are imbedded; his fourfold division of causes could not be estimated rightly even by Bacon, Descartes, or Spinoza; while his arrangement of the sciences, his remarks on classification, and his contributions to comparative biology bring us up to the very verge of theories whose first promulgation is still fresh in the memories of men.