(Καρνεάδης).

1. The son of Epicomus or Philocomus, was born at Cyrene about the year B. C. 213. He went early to Athens, and attended the lectures of the Stoics, and learnt there logie from Diogenes. His opinions, however, on philosophical subjects differed from those of his master, and he was fond of telling him, "if I reason right, I am satisfied; if wrong, give back the mina," which was the fee for the logic lectures. He was six years old when Chrysippus died, and never had any personal intercourse with him; but he deeply studied his works, and exerted all the energy of a very acute and original mind in their refutation. To this exercise he attributed his own eminence, and often repeated the words εἰ μὴ γὰρ ἦν Χρύσιππος, οὐκ ἄν ἦν ἐγὼ.

He attached himself as a zealous partizan to the Academy, which had suffered severely from the attacks of the Stoics; and on the death of Hegesinus, he was chosen to preside at the meetings of Academy, and was the fourth in succession from Arcesilaus. His great eloquence and skill in argument revived the glories of his school; and, defending himself in the negative vacancy of asserting nothing (not even that nothing can be asserted), carried on a vigorous war against every position that had been maintained by other sects.

In the year B. C. 155, when he was fifty-eight years old, he was chosen with Diogenes the Stoic and Critolaus the Peripatetic to go as ambassador to Rome to deprecate the fine of 500 talents which had been imposed on the Athenians for the destruction of Oropus. During his stay at Rome, he attracted great notice from his eloquent declamations on philosophical subjects, and it was here that, in the presence of Cato the Elder, he delivered his famous orations on Justice. The first oration was in commendation of the virtue, and the next day the second was delivered, in which all the arguments of the first were answered, and justice was proved to be not a virtue, but a mere matter of compact for the maintenance of civil society. The honest mind of Cato was shocked at this, and he moved the senate to send the philosopher home to his school, and save the Roman youth from his demoralizinge doctrines.

Carneades lived twenty-seven years after this at Athens, and died at the advanced age of eighty-five, or (according to Cicero) 90, B. C. 129. He is described as a man of unwearied industry. He was so engrossed in his studies, that he let his hair and nails grow to an immoderate iength, and was so absent at his own table (for he would never dine out), that his servant and concubine, Melissa, was constantly obliged to feed him. In his old age, he suffered from cataract in his eyes, which he bore with great impatience, and was so little resigned to the decay of nature, that he used to ask angrily, if this was the way in which nature undid what she had done, and sometimes expressed a wish to poison himself.

Carneades left no writings, and all that is known of his lectures is derived from his intimate friend and pupil, Cleitomachus; but so true was he to his own principles of witholding assent, that Cleitomachus confesses he never could ascertain what his master really thought on any subject. He, however, appears to have defended atheism, and consistently enough to have denied that the world was the result of anything but chance. In ethics, which more particularly were the subject of his long and laborious study, he seems to have denied the conformity of the moral ideas with nature. This he particularly insisted on in the second oration on Justice, in which he manifestly wished to convey his own notions on the subject; and he there maintains that ideas of justice are not derived from nature, but that they are purely artificial for purposes of expediency.

All this, however, was nothing but the special application of his general theory, that man did not possess, and never could possess, any criterion of truth.

Carneades argued that, if there were a criterion, it must exist either in reason (λόγος), or sensation (αἴσθησις), or conception (φαντασία). But then reason itself depends on conception, and this again on sensation; and we have no means of judging whether our sensations are true or false, whether they correspond to the objects that produce them, or carry wrong impressions to the mind, producing false conceptions and ideas, and leading reason also into error. Therefore sensation, conception, and reason, are alike disqualified for being the criterion of truth,

But after all, man must live and act, and must have some rule of practical life; therefore, although it is impossible to pronounce anything as absolutely true, we may yet establish probabilities of various degrees. For, although we cannot say that any given conception or sensation is in itself true, yet some sensations appear to us more true than others, and we must be guided by that which seems the most true. Again, sensations are not single, but generally combined with others,which either confirm or contradict them; and the greater this combination the greater is the probability of that being true which the rest combine to confirm; and the case in which the greatest number of conceptions, each in themselves apparently most true, should combine to affirm that which also in itself appears most true, would present to Carneades the highest probability, and his nearest approach to truth.

But practical life needed no such rule as this, and it is difficult to conceive a system more barren of all help to man than that of Carneades. It is not, indeed, probable that he aspired to any such designs of benefiting mankind, or to anything beyond his own celebrity as an acute reasoner and an eloquent speaker. As such he represented the spirit of an age when philosophy was fast losing the earnest and serious spirit of the earlier schools, and was degenerating to mere purposes of rhetorical display. (D. L. 4.62-66; Orelli, Onom. Tull. ii. p. 130, &c., where are given all the passages of Cicero, in which Carneades is mentioned ; Sextus Empiricus, Adv. Math. 7.159, &c.; Ritter, Gesch. Phil. 11.6; Brucker, Hist. Phil. i. p. 759, &c., vi. p. 237, &c.)