Neither Parmenides, nor Herakleitus, nor the Pythagoreans were dialecticians. They gave out their own thoughts in their own way, with little or no regard to dissentients. They did not cultivate the art of argumentative attack or defence, nor the correct application and diversified confrontation of universal terms, which are the great instruments of that art. It was Zeno, the disciple of Parmenides, that first employed dialectic in support of his master’s theory, or rather against the counter-theories of opponents. He showed by arguments memorable for their subtlety, that the hypothesis of an Absolute, composed of Entia Plura Discontinua, led to consequences even more absurd than those that opponents deduced from the Parmenidean hypothesis of Ens Unum Continuum. The dialectic, thus inaugurated by Zeno, reached still higher perfection in the colloquies of Sokrates; who not only employed a new method, but also introduced new topics of debate — ethical, political, and social matters instead of physical things and the Kosmos.
The peculiar originality of Sokrates is well known: a man who wrote nothing, but passed his life in indiscriminate colloquy with every one; who professed to have no knowledge himself, but interrogated others on matters that they talked about familiarly and professed to know well; whose colloquies generally ended by puzzling the respondents, and by proving to themselves that they neither knew nor could explain even matters that they had begun by affirming confidently as too clear to need explanation. Aristotle tells us[1] that Sokrates was the first that set himself expressly and methodically to scrutinize the definitions of general or universal terms, and to confront them, not merely with each other, but also, by a sort of inductive process, with many particular cases that were, or appeared to be, included under them. And both Xenophon and Plato give us abundant examples of the terms to which Sokrates applied his interrogatories: What is the Holy? What is the Unholy? What is the Beautiful or Honourable? What is the Ugly or Base? What is Justice-Injustice — Temperance — Madness — Courage — Cowardice — A City — A man fit for civil life? What is the Command of Men? What is the character fit for commanding men? Such are the specimens, furnished by a hearer,[2] of the universal terms whereon the interrogatories of Sokrates bore. All of them were terms spoken and heard familiarly by citizens in the market-place, as if each understood them perfectly; but when Sokrates, professing his own ignorance, put questions asking for solutions of difficulties that perplexed his own mind, the answers showed that these difficulties were equally insoluble by respondents, who had never thought of them before. The confident persuasion of knowledge, with which the colloquy began, stood exposed as a false persuasion without any basis of reality. Such illusory semblance of knowledge was proclaimed by Sokrates to be the chronic, though unconscious, intellectual condition of his contemporaries. How he undertook, as the mission of a long life, to expose it, is impressively set forth in the Platonic Apology.
[1] Metaphysica, A. p. 987, b. 2; M. p. 1078, b. 18.
[2] Xenophon Memorab. I. i. 16; IV. vi. 1-13.
It was thus by Sokrates that the meaning of universal terms and universal propositions, and the relation of each respectively to particular terms and particular propositions were first made a subject of express enquiry and analytical interrogation. His influence was powerful in imparting the same dialectical impulse to several companions; but most of all to Plato, who not only enlarged and amplified the range of Sokratic enquiry, but also brought the meaning of universal terms into something like system and theory, as a portion of the conditions of trustworthy science. Plato was the first to affirm the doctrine afterwards called Realism, as the fundamental postulate of all true and proved cognition. He affirmed it boldly, and in its most extended sense, though he also produces (according to his frequent practice) many powerful arguments and unsolved objections against it. It was he (to use the striking phrase of Milton[3]) that first imported into the schools the portent of Realism. The doctrine has been since opposed, confuted, curtailed, transformed, diversified in many ways; but it has maintained its place in logical speculation, and has remained, under one phraseology or another, the creed of various philosophers, from that time down to the present.
[3] See the Latin verses ‘De Ideâ Platonicâ quemadmodum Aristoteles intellexit’ —
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“At tu, perenne ruris Academi decus, Hæc monstra si tu primus induxti scholis,� &c. |
The following account of the problems of Realism was handed down to the speculations of the mediæval philosophers by Porphyry (between 270-300 A.D.), in his Introduction to the treatise of Aristotle on the Categories. After informing Chrysaorius that he will prepare for him a concise statement of the doctrines of the old philosophers respecting Genus, Differentia, Species, Proprium, Accidens, “abstaining from the deeper enquiries, but giving suitable development to the more simple,� — Porphyry thus proceeds:— “For example, I shall decline discussing, in respect to Genera and Species, (1) Whether they have a substantive existence, or reside merely in naked mental conceptions; (2) Whether, assuming them to have substantive existence, they are bodies or incorporeals; (3) Whether their substantive existence is in and along with the objects of sense, or apart and separable. Upon this task I shall not enter, since it is of the greatest depth, and requires another larger investigation; but shall try at once to show you how the ancients (especially the Peripatetics), with a view to logical discourse, dealt with the topics now propounded.�[4]
[4] Porphyry, Introd. in Categor. init. p. 1, a. 1, Schol. Br.
Before Porphyry, all these three problems had been largely debated, first by Plato, next by Aristotle against Plato, again by the Stoics against both, and lastly by Plotinus and the Neo-Platonists as conciliators of Plato with Aristotle. After Porphyry, problems the same, or similar, continued to stand in the foreground of speculation, until the authority of Aristotle became discredited at all points by the influences of the sixteenth and seventeenth centuries. But in order to find the beginning of them, as questions provoking curiosity and opening dissentient points of view to inventive dialecticians, we must go back to the age and the dialogues of Plato.