FORE:According to Aristotle, the Heracleitean flux was inconsistent with the highest law of thought, and made all predication impossible. It has been shown that the master himself recognised a fixed recurring order of change which could be affirmed if nothing else could. But the principle of change, once admitted, seemed to act like a corrosive solvent, too powerful for any vessel to contain. Disciples were soon found who pushed it to extreme consequences with the effect of abolishing all certainty whatever. In Platos time it was impossible to argue with a Heracleitean; he could never be tied down to a definite statement. Every proposition became false as soon as it was uttered, or rather before it was out of the speakers mouth. At last, a distinguished teacher of the school declined to commit himself by using words, and disputed exclusively in dumb show. A dangerous speculative crisis had set in. At either extremity of the Hellenic world the path of scientific inquiry was barred; on the one hand by a theory eliminating non-existence from thought, and on the other hand by a theory identifying it with existence. The26 luminous beam of reflection had been polarised into two divergent rays, each light where the other was dark and dark where the other was light, each denying what the other asserted and asserting what the other denied. For a century physical speculation had taught that the universe was formed by the modification of a single eternal substance, whatever that substance might be. By the end of that period, all becoming was absorbed into being at Elea, and all being into becoming at Ephesus. Each view contained a portion of the truth, and one which perhaps would never have been clearly perceived if it had not been brought into exclusive prominence. But further progress was impossible until the two half-truths had been recombined. We may compare Parmenides and Heracleitus to two lofty and precipitous peaks on either side of an Alpine pass. Each commands a wide prospect, interrupted only on the side of its opposite neighbour. And the fertilising stream of European thought originates with neither of them singly, but has its source midway between.Whenever naturalism and scepticism have thus stood opposed, the result has been their transformation or absorption into a new philosophy, combining the systematic formalism of the one with the introspective idealism of the other. In Greece such a revolution had already been effected once before by Plato; and a restoration of his system seemed the most obvious solution that could offer itself on the present occasion. Such was, in fact, the solution eventually adopted; what we have to explain is why its adoption was delayed so long. For this various reasons may be offered. To begin with, the speculative languor of the age was unfavourable to the rise of a new school. Greece was almost depopulated by the demands of foreign service; and at Alexandria, where a new centre of Hellenism had been created, its best energies were absorbed by the cultivation of positive science. It was, no doubt, in great part owing to the dearth of ability that ideas which, at an earlier period, would have been immediately taken up and developed, were allowed to remain stationary for a hundred yearsthe interval separating a Carneades from an Arcesilaus. The regular organisation of philosophical teaching was another hindrance to progress. A certain amount of property was annexed to the headships of the different schools, and served as an endowment, not of research but of contented acquiescence in the received traditions. Moreover, the jealousy with which the professors of rival doctrines would naturally regard one another, was likely to prevent their mutual approximation from going beyond160 certain not very close limits, and might even lead to a still severer definition of the characteristic tenets which still kept them apart. Another and deeper disturbing force lay in the dissensions which, at a very early stage of its development, had split the spiritualistic philosophy into two opposing tendencies respectively represented by Plato and Aristotle. Any thinker who wandered away from the principles either of Stoicism or of Scepticism was more likely to find himself bewildered by the conflicting claims of these two illustrious masters, than to discern the common ground on which they stood, or to bring them within the grasp of a single reconciling system. Finally, an enormous perturbation in the normal course of speculation was produced by the entrance of Rome on the philosophical scene. But before estimating the influence of this new force, we must follow events to the point at which it first becomes of calculable importance.
