Aristotelian schools therefore were predominantly ethical, sensationalist, and materialist, as opposed to the idealistic metaphysics of the preceding age.

Of these schools the least original and the least important is the Peripatetic. The immediate successor of Aristotle was Theophrastus, whose Characters and treatises on Botany we still possess, together with fragments of other works. He appears to have carried further his master's investigations upon particular points, without diverging from his general principles. Cicero charges him with assigning too much weight to fortune as an element of happiness. Strato, who succeeded him as head of the Lyceum in 287 B.C., dethroned the Nous of Aristotle, and explained the ordered movement of the universe by ascribing 'to the several parts of matter an inward plastic life, whereby they could artificially frame themselves to the best advantage according to their several capabilities without any conscious or reflexive knowledge'.' Cicero says that he is omnino semovendus from the true Peripatetics, as he abandoned ethics and departed very widely from his predecessors in physics, to which he confined himself. Aristoxenus and Dicaearchus were contemporaries of Theophrastus; the former is chiefly known as the writer of the first scientific treatise on Music, the latter was a voluminous popular writer much esteemed by Cicero. He denied the immortality of the soul. After the time of Andronicus, mentioned above, the Peripatetics were chiefly known as laborious commentators. Cratippus presided over the school during the lifetime of Cicero, who sent young Marcus to Athens to attend his lectures.

The first name among the Sceptics is Pyrrho of Elis (fl. about 320 B.C.), who is said to have had some connexion with the Megarian and the Atomic schools, and to have accompanied Alexander on his expedition into India, and thus learnt something of the doctrines of the Magi and the Indian Gymnosophists. Perhaps the influence of the latter may be traced in the three positions attributed to him, (1) that the wise man should practise ox, suspension of judgment, (2) that all external things are adiapopa, matters of indifference to him, (3) that he will thus be free from passion and anxiety, and arrive at the condition of complete atapaέía, imperturbability. Pyrrho left no writings, but his pupil, Timon of Phlius (fl. 280 B.C.), was a voluminous writer. We have a few fragments of his Silli, a satirical poem in which he ridiculed the tenets of other philosophers. When the Academy became sceptical there was no room for an independent Pyrrhonist school, but it revived in the person of Aenesidemus when the Academy became identified with an eclectic dogmatism under Antiochus. The sceptical argument was summed up in ten τρóжоι, and is given in full in the works of Sextus Empiricus (fl. 200 A.D.). The most important points in it are as follows: (1) the discrepancy of opinions among wise and honest men, (2) the relativity of all knowledge, i.e. the manner in which it varies with the physical and mental conditions of the observer or thinker, (3) the impossibility of proving the first principles on which proof is based, (4) the petitio principii involved in the syllogism, the major premiss assuming the truth of the conclusion.

We turn back now to trace the fortunes of the Academy,

which may be conveniently divided into three schools, the Old, the Middle or Sceptical, and the Reformed or Eclectic Academy'. To the first belong the names of Speusippus Xenocrates and Polemo, who successively presided over the school between 347 and 270 B. C., as well as those of Heraclides of Pontus, Crantor and Crates. They appear to have modified the Platonic doctrines mainly by the admixture of Pythagorean elements. Crantor's writings were used by Cicero for his Consolatio and Tusculan Disputations. The chief expounders of the Middle Academy were its founder Arcesilaus 315-241 B. C., (characterized in a line borrowed from the Homeric description of the Chimaera as πρόσθε Πλάτων, όπιθεν Πύρ ῥων, μέσσος Διόδωρος, implying that by his dialectic quibbling he had changed the Platonism, which he professed, into a mere Pyrrhonism), Carneades of Cyrene 214-129 B.C., one of the Athenian ambassadors to Rome in 155 B.C., and Clitomachus of Carthage, the literary exponent of the views of his master Carneades, who is said to have never written anything himself. They neglected the positive doctrine of Plato, and employed themselves mainly in a negative polemic against the dogmatism

1 Cicero only recognized the Old and the New Academy, the latter corresponding to what is above called the Middle Academy, but including Philo. Antiochus himself claimed to be a true representative of the Old Academy. Later writers made five Academic schools, the second founded by Arcesilaus, the third by Carneades, the fourth by Philo, the fifth by Antiochus.

2 Carneades had an extraordinary reputation for acuteness and skill in argument, as is shown by a line of Lucilius (preserved by Lactantius V. 15), in which Neptune speaks of some question as insoluble even to a Carneades, nec si Carneaden ipsum ad nos Orcu' remittat.

of the Stoics, professing to follow the example of Socrates, though they thought that even he had approached too near to dogmatism in saying that he knew that he knew nothing. Probable opinion was the furthest point in the direction of knowledge to which man could attain.

Cicero, in his Natura Deorum and Academica, and Sextus Empiricus have preserved to us several specimens of the arguments used by Carneades in order to prove the impossibility of the attainment of knowledge in the abstract, as well as to expose the errors and inconsistency of the knowledge professed by the Dogmatic schools of his time. Thus, if there is such a thing as knowledge, it must rest ultimately on the senses; but the senses are constantly deceptive, and we have no means of distinguishing between a true and a false sensation, the difference between objects being often so imperceptible that we are liable to mistake one for another. The impotence of reasoning as an instrument for the attainment of certain truth is shown by the Sorites and other logical puzzles. Dialectic only tests formal accuracy of procedure, it cannot assure us of the truth of that which we assume as the foundation of our reasoning. Like the polypus which feeds on its own limbs, it can destroy, but never establish proof. The Stoics allege universal consent as a proof of the existence of God. But this consent is not proved, and, if it were, the opinion of the ignorant has no weight. The Stoics further maintain that the world exhibits the perfection of reason in its constitution and that Divine Providence directs all things for the good of men. But many things exist for which we can see no reason, many which are distinctly injurious to mankind. Even the possession of reason is a very doubtful advan

tage; and we do not find that the wise and virtuous man is always prosperous. Granting that the world is perfect, why may not this perfection be the result of the unconscious working of nature? Why are we bound to attribute it to the action of an intelligent Being? Again it is impossible to form any consistent conception of God. The ideas of personality and infinity are mutually contradictory. Even to think of Him as the living God or the good God, is opposed to reason. For animal life is necessarily joined with feeling, and feeling implies consciousness of pleasure and pain, but whatever is capable of pain is liable to destruction by excess of pain. And how can we ascribe virtue to a Being who is supposed to have no weaknesses to conquer, no temptations to resist; who being all-powerful can have no need of prudence to devise means for attaining his ends, no need of courage to sustain him against danger? It is equally impossible to think of God either as corporeal or incorporeal. If he is the former, he must be either simple or compound: if he is compounded of different elements, he is naturally liable to dissolution; if he is a pure elementary substance, he must be without life and thought. On the other hand that which is incorporeal can neither feel nor act. In like manner it may be shown that it is impossible to make any assertion whatever about God.

But though knowledge and certainty are unattainable, we are not left simply to act at hazard. Probability was the guide of life to Carneades, as to Bp. Butler; and he carefully distinguished degrees of probability. Thus a sensation might be of such a nature as to produce in us belief involuntarily; this he called parraσía milavý, a persuasive presentation. Again, no sensation comes.