THREE:The modern doctrine of evolution, while relying largely on the fertility of multiplied chances, is not obliged to assume such an enormous number of simultaneous coincidences as Epicurus. The ascription of certain definite attractions and repulsions to the ultimate particles of matter would alone restrict their possible modes of aggregation within comparatively narrow limits. Then, again, the world seems to have been built up by successive stages, at each of which some new force or combination of forces came into play, a firm basis having been already secured for whatever variations they were capable of producing. Thus the solar system is a state of equilibrium resulting from the action of two very simple forces, gravitation and heat. On the surface of the earth, cohesion and chemical affinity have been superadded. When a fresh equilibrium had resulted from their joint energy, the more complex conditions of life found free scope for their exercise. The transformations of living species were similarly effected by variation on variation. And, finally, in one species, the satisfaction of its animal wants set free those more refined impulses by which, after many experiments, civilisation has been built up. Obviously the total sum of adaptations necessary to constitute our actual world will have the probabilities of its occurrence enormously increased if we suppose the more general conditions to be established prior to, and in complete independence of, the less general, instead of limiting ourselves, like the ancient atomists, to one vast simultaneous shuffle of all the material and dynamical elements involved.But before the dissolving action of Nominalism had become fully manifest, its ascendency was once more challenged; and this time, also, the philosophical impulse came from Constantinople. Greek scholars, seeking help in the West, brought with them to Florence the complete works of Plato; and these were shortly made accessible to a wider public through the Latin translation of Ficino. Their influence seems at first to have told in favour of mysticism, for this was the contemporary tendency to which they could be most readily affiliated; and, besides, in swinging back from Aristotle��s philosophy to the rival form of spiritualism, men��s minds naturally reverted, in the first instance, to what had once linked them together��the system of Plotinus. Thus Platonism was studied through an Alexandrian medium, and as the Alexandrians had looked at it, that is to say, chiefly under its theological and metaphysical aspects. As such, it became the accepted philosophy of the Renaissance;369 and much of what we most admire in the literature��at least the English literature��of that period, is directly traceable to Platonic influence. That the Utopia of Sir Thomas More was inspired by the Republic and the Critias is, of course, obvious; and the great part played by the ideal theory in Spenser��s Faery Queen, though less evident, is still sufficiently clear. As Mr. Green observes in his History of the English People (II., p. 413), ��Spenser borrows, in fact, the delicate and refined forms of the Platonic philosophy to express his own moral enthusiasm.... Justice, Temperance, Truth are no mere names to him, but real existences to which his whole nature clings with a rapturous affection.�� Now it deserves observation, as illustrating a great revolution in European thought, that the relation of Plato to the epic of the English Renaissance is precisely paralleled by the relation of Aristotle to the epic of mediaeval Italy. Dante borrows more than his cosmography from the Stagirite. The successive circles of Hell, the spirals of Purgatory, and the spheres of Paradise, are a framework in which the characters of the poem are exhibited, not as individual actors whom we trace through a life��s history, but as types of a class and representatives of a single mental quality, whether vicious or virtuous. In other words, the historical arrangement of all previous poems is abandoned in favour of a logical arrangement. For the order of contiguity in time is substituted the order of resemblance and difference in idea. How thoroughly Aristotelian, indeed, were the lines within which mediaeval imagination moved is proved by the possibility of tracing them in a work utterly different from Dante��s��the Decameron of Boccaccio. The tales constituting this collection are so arranged that each day illustrates some one special class of adventures; only, to make good Aristotle��s principle that earthly affairs are not subject to invariable rules, a single departure from the prescribed subject is allowed in each decade; while370 during one entire day the story-tellers are left free to choose a subject at their own discretion.