Thus Socrates pulled away all the foundations on which a false science had been erected, and indicated the mode by which alone the true could be established. Here he was not unlike Bacon, who pointed out the way whereby science could be advanced, without founding any school or advocating any system; but the Athenian was unlike Bacon in the object of his inquiries. Bacon was disgusted with ineffective logical speculations, and Socrates with ineffective physical researches. He never suffered a general term to remain undetermined, but applied it at once to particulars, and by questions the purport of which was not comprehended. It was not by positive teaching, but by exciting scientific impulse in the minds of others, or stirring up the analytical faculties, that Socrates manifested originality. It was his aim to force the seekers after truth into the path of inductive generalization, whereby alone trustworthy conclusions could be formed. He thus struck out from his own and other minds that fire which sets light to original thought and stimulates analytical inquiry. He was a religious and intellectual missionary, preparing the way for the Platos and Aristotles of the succeeding age by his severe dialectics. This was his mission, and he declared it by talking. He did not lecture; he conversed. For more than thirty years he discoursed on the principles of morality, until he arrayed against himself enemies who caused him to be put to death, for his teachings had undermined the popular system which the Sophists accepted and practised. He probably might have been acquitted if he had chosen to be, but he did not wish to live after his powers of usefulness had passed away.
The services which Socrates rendered to philosophy, as enumerated by Tennemann, "are twofold,--negative and positive. Negative, inasmuch as he avoided all vain discussions; combated mere speculative reasoning on substantial grounds; and had the wisdom to acknowledge ignorance when necessary, but without attempting to determine accurately what is capable and what is not of being accurately known. Positive, inasmuch as he examined with great ability the ground directly submitted to our understanding, and of which man is the centre."
Socrates cannot be said to have founded a school, like Xenophanes. He did not bequeath a system of doctrines. He had however his disciples, who followed in the path which he suggested. Among these were Aristippus, Antisthenes, Euclid of Megara, Phaedo of Elis, and Plato, all of whom were pupils of Socrates and founders of schools. Some only partially adopted his method, and each differed from the other. Nor can it be said that all of them advanced science. Aristippus, the founder of the Cyreniac school, was a sort of philosophic voluptuary, teaching that pleasure is the end of life. Antisthenes, the founder of the Cynics, was both virtuous and arrogant, placing the supreme good in virtue, but despising speculative science, and maintaining that no man can refute the opinions of another. He made it a virtue to be ragged, hungry, and cold, like the ancient monks; an austere, stern, bitter, reproachful man, who affected to despise all pleasures,--like his own disciple Diogenes, who lived in a tub, and carried on a war between the mind and body, brutal, scornful, proud. To men who maintained that science was impossible, philosophy is not much indebted, although they were disciples of Socrates. Euclid--not the mathematician, who was about a century later--merely gave a new edition of the Eleatic doctrines, and Phaedo speculated on the oneness of "the good."
It was not till Plato arose that a more complete system of philosophy was founded. He was born of noble Athenian parents, 429 B.C., the year that Pericles died, and the second year of the Peloponnesian War,--the most active period of Grecian thought. He had a severe education, studying mathematics, poetry, music, rhetoric, and blending these with philosophy. He was only twenty when he found out Socrates, with whom he remained ten years, and from whom he was separated only by death. He then went on his travels, visiting everything worth seeing in his day, especially in Egypt. When he returned he began to teach the doctrines of his master, which he did, like him, gratuitously, in a garden near Athens, planted with lofty plane-trees and adorned with temples and statues. This was called the Academy, and gave a name to his system of philosophy. It is this only with which we have to do. It is not the calm, serious, meditative, isolated man that I would present, but his contribution to the developments of philosophy on the principles of his master. Surely no man ever made a richer contribution to this department of human inquiry than Plato. He may not have had the originality or keenness of Socrates, but he was more profound. He was pre-eminently a great thinker, a great logician, skilled in dialectics; and his "Dialogues" are such perfect exercises of dialectical method that the ancients were divided as to whether he was a sceptic or a dogmatist. He adopted the Socratic method and enlarged it. Says Lewes:--
"Analysis, as insisted on by Plato, is the decomposition of the whole into its separate parts,--is seeing the one in many.... The individual thing was transitory; the abstract idea was eternal. Only concerning the latter could philosophy occupy itself. Socrates, insisting on proper definitions, had no conception of the classification of those definitions which must constitute philosophy. Plato, by the introduction of this process, shifted philosophy from the ground of inquiries into man and society, which exclusively occupied Socrates, to that of dialectics."
Plato was also distinguished for skill in composition. Dionysius of Halicarnassus classes him with Herodotus and Demosthenes in the perfection of his style, which is characterized by great harmony and rhythm, as well as by a rich variety of elegant metaphors.
Plato made philosophy to consist in the discussion of general terms, or abstract ideas. General terms were synonymous with real existences, and these were the only objects of philosophy. These were called Ideas; and ideas are the basis of his system, or rather the subject-matter of dialectics. He maintained that every general term, or abstract idea, has a real and independent existence; nay, that the mental power of conceiving and combining ideas, as contrasted with the mere impressions received from matter and external phenomena, is the only real and permanent existence. Hence his writings became the great fountain-head of the Ideal philosophy. In his assertion of the real existence of so abstract and supersensuous a thing as an idea, he probably was indebted to Pythagoras, for Plato was a master of the whole realm of philosophical speculation; but his conception of ideas as the essence of being is a great advance on that philosopher's conception of numbers. He was taught by Socrates that beyond this world of sense there is the world of eternal truth, and that there are certain principles concerning which there can be no dispute. The soul apprehends the idea of goodness, greatness, etc. It is in the celestial world that we are to find the realm of ideas. Now, God is the supreme idea. To know God, then, should be the great aim of life. We know him through the desire which like feels for like. The divinity within feels its affinity with the divinity revealed in beauty, or any other abstract idea. The longing of the soul for beauty is love. Love, then, is the bond which unites the human with the divine. Beauty is not revealed by harmonious outlines that appeal to the senses, but is truth; it is divinity. Beauty, truth, love, these are God, whom it is the supreme desire of the soul to comprehend, and by the contemplation of whom the mortal soul sustains itself. Knowledge of God is the great end of life; and this knowledge is effected by dialectics, for only out of dialectics can correct knowledge come. But man, immersed in the flux of sensualities, can never fully attain this knowledge of God, the object of all rational inquiry. Hence the imperfection of all human knowledge. The supreme good is attainable; it is not attained. God is the immutable good, and justice the rule of the universe. "The vital principle of Plato's philosophy," says Ritter, "is to show that true science is the knowledge of the good, is the eternal contemplation of truth, or ideas; and though man may not be able to apprehend it in its unity, because he is subject to the restraints of the body, he is nevertheless permitted to recognize it imperfectly by calling to mind the eternal measure of existence by which he is in his origin connected." To quote from Ritter again:--
"When we review the doctrines of Plato, it is impossible to deny that they are pervaded with a grand view of life and the universe. This is the noble thought which inspired him to say that God is the constant and immutable good; the world is good in a state of becoming, and the human soul that in and through which the good in the world is to be consummated. In his sublimer conception he shows himself the worthy disciple of Socrates.... While he adopted many of the opinions of his predecessors, and gave due consideration to the results of the earlier philosophy, he did not allow himself to be disturbed by the mass of conflicting theories, but breathed into them the life-giving breath of unity. He may have erred in his attempts to determine the nature of good; still he pointed out to all who aspire to a knowledge of the divine nature an excellent road by which they may arrive at it."
That Plato was one of the greatest lights of the ancient world there can be no reasonable doubt. Nor is it probable that as a dialectician he has ever been surpassed, while his purity of life and his lofty inquiries and his belief in God and immortality make him, in an ethical point of view, the most worthy of the disciples of Socrates. He was to the Greeks what Kant was to the Germans; and these two great thinkers resemble each other in the structure of their minds and their relations to society.
The ablest part of the lectures of Archer Butler, of Dublin, is devoted to the Platonic philosophy. It is at once a criticism and a eulogium. No modern writer has written more enthusiastically of what he considers the crowning excellence of the Greek philosophy. The dialectics of Plato, his ideal theory, his physics, his psychology, and his ethics are most ably discussed, and in the spirit of a loving and eloquent disciple. Butler represents the philosophy which he so much admires as a contemplation of, and a tendency to, the absolute and eternal good. As the admirers of Ralph Waldo Emerson claim that he, more than any other man of our times, entered into the spirit of the Platonic philosophy, I introduce some of his most striking paragraphs of subdued but earnest admiration of the greatest intellect of the ancient Pagan world, hoping that they may be clearer to others than they are to me:--