Did Greek philosophy die with Proclus? The political changes of the time forced alteration of dialect and position; but the accumulations of mental achievements could not perish. This again we owe to Proclus. Besides being the first great commentator he precipitated his most valuable achievements in logical form, in analytic arrangement, in the form of crystal-clear propositions, theorems, demonstrations, and corollaries. Such a highly abstract form was inevitable, inasmuch as Numenius had turned away from Aristotelian observation of nature. Just like the Hebrew thinkers, who finally became commentators and abstract theorizers, nothing else was left for a philosophy without connection with experiment, when whittled down by the keenest intellects of the times.
This abstract method, still familiarly used by geometry, reappeared among the School-men, notably in Thomas Aquinas. Later it persisted with Spinoza and Descartes. However, rising experimentalism has gradually terminated it, its last form appearing in Kant and Hegel. Kant's "Ding in sich," reached after abstracting all qualities, is only a re-statement of Numenius and Plotinos's "subject," or, definition of matter; and Hegel's dialectic, beginning with Being and Not-being, more definitely proclaimed by Plotinos, goes as far back as the Eleatics and Heraclitus, not to mention Plato. However, Kant and Hegel are the great masters of modern thought; and although at one time the rising tide of materialism and cruder forms of evolution threatened to obscure it, Karl Pearson's "Grammar of Science," generous as it is in invective against Kant and Hegel, in modern terms clinches Berkeley's and Kant's demonstration of the reality of the super-sensual, thus vindicating Plotinos, and, before him, Numenius.
It must not be supposed that in thus tracing the springs of our modern thought we necessarily approve of all the thought of Plotinos, Numenius or Plato. On the contrary, they were far more likely to have committed logical errors than we are, because they were hypnotized by the glamor of the terms they used, which to us are mere laboratory tools. The best way to prove this will be to appraise at its logical value for us Plotinos's discussion of Matter, elsewhere studied in its value for us.
III. PLOTINOS'S VIEW OF MATTER.
We have elsewhere pointed out the hopelessness of escaping either aspect of the problem of the One and the Many; and that the attempt of the Stoics to avoid the Platonic dualism by a materialistic monism was merely a change of names, the substance of the dualism remaining as the opposition of the contraries, such as active and passive, male and female, the predominant elements,[474] etc. Plotinos, in his abandonment of Numenian dualism, and championing of Stoicism, undertaking the feud with the Gnostics, the successors of Numenius, must therefore have inherited the same difficulties of thought, and we shall see how in spite of his mental agility he is caught in the same traditional meshes, and that these irreducible difficulties occur in each one of his three periods of life, the Eustochian, the Amelian, and the Porphyrian.
In the Amelian, he teaches two matters, the physical and the intelligible, by which device he seeks to avoid the difficulties of dualism, crediting to intelligible matter any necessary form of Being, thus pushing physical matter into the outer darkness of non-being. So intelligible matter is still a form of Being, and we still hold to monism; as intelligible matter may participate in the good; while matter physical remains evil, being a deprivation of good, not possessing it. This, of course is dualism; and he thus has a convenient pun on the word matter, by which he can be monist or dualist, as the fancy takes him, or as exigencies demand. This participation, therefore, does not eliminate the dualism, while formally professing monism. Therefore Plotinos tries to choose between monism and dualism by surreptitiously accepting both.
In the Porphyrian period, he rejected the idea of intelligible matter.[475] Forced to fashion entirely new arguments, he seizes as tool the Aristotelian distinction between potentiality and actuality, or energy as dynamic accomplishment.[476] But no logical device can help a man to pull himself up by his boot-straps. If by Being you mean existence, then its opposite must be negative, and to speak of real non-being, as something that shares being, is an evasion. To say that matter remains non-being, while having the possibility of future Being, which however can never be actualized, is mere juggling with words. Even if matter is no more than a weak, confused image, it is not non-being. If it is a positive lie, it is not non-being. To talk of a higher degree of Non-being, that is real non-being, is simply to confuse the actuality intended with the thought of non-being, which of course is a thought as actually existing as any other. Moreover if matter is imperishable, it cannot be non-being; and if it possesses Being potentially, it certainly is not non-existence. The Aristotelian potentiality could help to create this evasion, but did not remove its real nature; it merely supplied Plotinos with an intellectual device to characterize something that would not be actually existing as still having the possibility of existence; but this is not non-existence. In another writing[477] of this period Plotinos continues his evasions about the origin and nature of matter. First, he grants that it is something that is not original, being later than many earthly, and all intelligible objects; although, if he had returned to the conception of intelligible matter, he would have been at liberty to assert the originality of the latter. Then he holds that Being is common to both form and matter, as to quality, but not as to quantity. Last, he closes the paragraph by saying that perhaps form and matter do not come from the same origin, as there is a difference between them.
In Plotinos's third, or Eustochian period, the same evasions occur. For instance[478] he limits Being to goodness. Then he acknowledges the existence of evil things, and derives their evil quality from a primary evil, the "image of essence," the Being of evil. That he is conscious of having strained a point is evident from the fact that he adds the clause, "if there can be a Being of evil." Likewise,[479] while discussing evil, which is generally recognized because in our daily lives there is positive pain, and sensations of pain, he defines evil as lack of qualities. To say that evil is not such as to form, but as to nature is opposite to form is nonsense, inasmuch as life is full of positive evils, as Numenius brought out in 16, and Plotinos acknowledged even in spite of his polemic against the Gnostics.
Finally Plotinos takes refuge in a miracle[480] as explanation of "unparticipating participation." This is commentary enough; it shows he realized the futility of any arguments. But Plotinos was not alone in despairing of establishing an ironclad system; before him Numenius had, just as pathetically, despaired of a logical dualism, and he acknowledged in fragment 16 that Pythagoras's arguments, however true, were "wonderful and opposed to the belief of a majority of humanity."