This subjective direction already noticed was carried out to its farthest extent by the Sceptics, who broke down completely the bridge between subject and object, denying all objective truth, knowledge and science, and wholly withdrawing the philosopher from every thing but himself and his own subjective estimates. In this direction we may distinguish between the old Scepticism, the new Academy, and the later Scepticism.
1. The Old Scepticism.—Pyrrho of Elis, who was perhaps a cotemporary of Aristotle, was the head of the old Sceptics. He left no writings behind him, and we are dependent for a knowledge of his opinions upon his scholar and follower, Timon of Phlius. The tendency of these sceptical philosophers, like that of the Stoics and Epicureans, was a practical one, for philosophy, said they, ought to lead us to happiness. But in order to live happily we must know how things are, and, therefore, in what kind of a relation we stand to them. The first of these questions the Sceptics answered by attempting to show that all things, without exception, are indifferent as to truth and falsehood, uncertain, and in nowise subject to man’s judgment. Neither our senses nor our opinions concerning any thing teach us any truth; to every precept and to every position a contrary may be advanced, and hence the contradictory views of men, and especially of the philosophies of the schools respecting one and the same thing. All objective knowledge and science being thus impossible, the true relation of the philosopher to things consists in the entire suspension of judgment, and the withholding of every positive assertion. In order to avoid every thing like a positive assertion, the Sceptics had recourse to a variety of artifices, and availed themselves of doubtful modes of expression, such as it is possible; it may be so; perhaps; I assert nothing,—cautiously subjoining to this last—not even that I assert nothing. By this suspension of judgment the Sceptics thought they could attain their practical end, happiness; for the abstinence from all positive opinion is followed by a freedom from all mental disturbance, as a substance is by a shadow. He who has embraced Scepticism lives thenceforward tranquilly, without inquietude, without agitation, with an equable state of mind, and, in fact, divested of his humanity. Pyrrho is said to have originated the doctrine which lies at the basis of sceptical apathy, that no difference exists between sickness and health, or between life and death. The Sceptics, for the most part, derived the material for their views from the previous investigations in the dogmatic schools. But the grounds on which they rested were far from being profound, and were for the most part either dialectic errors which could easily be refuted, or mere subtleties. The use of the following ten tropes is ascribed to the old Sceptics, though these were perhaps not definitely brought out by either Pyrrho or Timon, but were probably first collected by Ænesidemus, soon after the time of Cicero. The withholding of all decisive judgment may rest; (1) upon the distinction generally existing between individual living objects; (2) upon the difference among men; (3) the different functions of the organs of sense; (4) the circumstances under which objects appear; (5) the relative positions, intervals, and places; (6) intermixtures; (7) the quantities and modifications of the objects we perceive; (8) relations; (9) the frequent or rare occurrence; (10) the different ways of life, the varieties of customs and laws, the mythical representations and dogmatic opinions of men.
2. The New Academy.—Scepticism, in its conflict with the Stoics, as it appeared in the Platonic school established by Arcesilaus (316-241), has a far greater significance than belongs to the performances of the Pyrrhonists. In this school Scepticism sought its support by its great respect for the writings and its transmission of the oral teachings of Plato. Arcesilaus could neither have assumed nor maintained the chair of instruction in the Academy, had he not carefully cherished and imparted to his disciples the impression that his own view, respecting the withholding of a decisive judgment, coincided essentially with that of Socrates and of Plato, and if he had not also taught that he only restored the genuine and original significance of Platonism, when he set aside the dogmatic method of teaching. An immediate incitement to the efforts of Arcesilaus is found in his opposition to the rigid dogmatic system which had lately arisen in the Porch, and which claimed to be in every respect an improvement upon Platonism. Hence, as Cicero remarks, Arcesilaus directed all his sceptical and polemic attacks against Zeno, the founder of Stoicism. He granted with his opponent that no representation should form a part of undoubted knowledge, if it could possibly have arisen through any other object than that from which it actually sprung, but he would not admit that there might be a notion which expressed so truly and accurately its own object, that it could not have arisen from any other. Accordingly, Arcesilaus denied the existence of a criterion which could certify to us the truth of our knowledge. If there be any truth in our affirmations, said he, we cannot be certain of it. In this sense he taught that one can know nothing, not even that he does know nothing. But in moral matters, in choosing the good and rejecting the evil, he taught that we should follow that which is probable.
Of the subsequent leaders in the new Academy, Carneades (214-129) alone need here be mentioned, whose whole philosophy, however, consists almost exclusively in a polemic against Stoicism and in the attempt to set up a criterion of truth. His positive performance is the attempt to bring out a philosophical theory of probabilities. The later Academicians fell back to an eclectic dogmaticism.
3. The later Scepticism.—Once more we meet with a peculiar Scepticism at the time when Grecian philosophy had wholly fallen to decay. To this time belong Ænesidemus, who probably—though this cannot be affirmed with certainty—lived but a little after Cicero; Agrippa, whose date is also uncertain, though subsequent to Ænesidemus, and Sextus Empiricus—i. e. a Grecian physician of the empiric sect, who probably flourished in the first half of the third century of the Christian era. These are the most significant names. Of these the last has the greatest interest for us, from two writings which he left behind him (the hypotyposes of Pyrrho in three books, and a treatise against the mathematicians in nine books), which are sources of much historical information. In these he has profusely collected every thing which the Scepticism of the ancients knew how to advance against the certainty of knowledge.
SECTION XX.
THE ROMANS.
The Romans have taken no independent part in the progress of philosophy. After Grecian philosophy and literature had begun to gain a foothold among them, and especially after three distinguished representatives of Attic culture and eloquence—Carneades the Academician, Critolaus the Peripatetic, and Diogenes the Stoic—had appeared in Rome as envoys from Athens; and after Greece, a few years later, had become a Roman province, and thus outwardly in a close connection with Rome, almost all the more significant systems of Grecian philosophy, especially the Epicurean (Lucretius), and the Stoic (Seneca), flourished and found adherents in Rome, though without gaining any real philosophical progress. The Romish philosophizing is wholly eclectic, as is seen in Cicero, the most important and influential philosophic writer among the Romans. But the popular philosophy of this man and of the minds akin to him cannot be strongly assailed, for, notwithstanding its want of originality and logical sequence, it gave philosophy a broad dissemination, and made it a means of universal culture.