Asscholarch (leader) of theAcademy, he was one of three philosophers sent toRome in 155 BC where his lectures on the uncertainty ofjustice caused consternation among leading politicians.[6][7][8] He left no writings.[9] His ideas were passed on to us through his successorClitomachus whose own books were lost but relayed to us indirectly in the writings ofCicero andSextus Empiricus.[10][11] He seems to have doubted the ability not just of thesenses but ofreason too in acquiringtruth. His skepticism was, however, moderated by the belief that we can, nevertheless, ascertain probabilities (not in the sense of statistical probability, but in the sense of persuasiveness)[12] of truth, to enable us to act.[13]
According toDouglas Walton, Carneades' most important contribution to philosophy was his theory of plausibility based on reasonable evidence. The 3 criteria, as relayed by Empiricus, for accepting an argument, even if tentatively, is that it should be presented in a convincing way, that it is consistent with other arguments put forward, and that it can be confirmed by testing. Walton argues that Carneades provided a pragmatic response to skepticism by asserting that reasonable grounds were sufficient for action and belief in daily life rather than absolute certainty.[14]
Carneades, the son of Epicomus or Philokomus, was born atCyrene,North Africa in 214/213 BC. He migrated early toAthens. There he attended the lectures of theStoics, learning their logic fromDiogenes of Babylon and studying the works ofChrysippus. He subsequently focused his efforts on refuting the Stoics, attaching himself to thePlatonic Academy, which had suffered from the attacks of the Stoics. On the death ofHegesinus of Pergamon, he was chosenscholarch (head) of the Academy. His great eloquence and skill in argument revived the glories of the Academic Skeptics. He asserted nothing (not even that nothing can be asserted), and carried on a vigorous argument against everydogma maintained by other sects.
In the year 155 BC, when he was fifty-eight years old, he was chosen with the StoicDiogenes of Babylon and thePeripateticCritolaus to go as ambassadors toRome to deprecate the fine of 500 talents which had been imposed on the Athenians for the destruction ofOropus. During his stay at Rome, he attracted great notice from his eloquent speeches on philosophical subjects. It was here that, in the presence ofCato the Elder, he delivered his several orations onjustice. The first oration was in commendation of thevirtue ofRoman justice. The next day he delivered the second oration, in which he refuted all the arguments he had made the day before. He persuasively attempted to prove that justice was inevitably problematic, and not a given when it came to virtue, but merely a compact device deemed necessary for the maintenance of a well-ordered society. This oration shocked Cato. Recognizing the potential danger of Carneades' arguments, Cato moved theRoman Senate to send Carneades back to Athens to prevent Roman youth from being exposed to a re-examining of Roman doctrines. Carneades lived twenty-seven years after this atAthens.
Due to Carneades' ill health, he was succeeded as scholarch by Polemarchus of Nicomedia (137/136 BC),[15] who died 131/130 BC and was succeeded by Crates of Tarsus.[16] Crates died in 127/126 BC and was succeeded byClitomachus.[16] Carneades died in 129/128 BC, at the advanced age of 85 (althoughCicero says 90).
Carneades 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 length, 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.Latin writer and authorValerius Maximus, to whom we owe the last anecdote, tells us that Carneades, before discussing withChrysippus, was wont to purge himself withhellebore, to have a sharper mind.[17] 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 topoison himself.[citation needed]
Carneades, depicted as a medieval scholar in theNuremberg Chronicle, where he is called "Carmeides".[18]
Carneades is known as anAcademic Skeptic. Academic Skeptics (so called because this was the type of skepticism taught inPlato'sAcademy inAthens) hold thatall knowledge is impossible, except for the knowledge that all other knowledge is impossible.
Carneades was so faithful to his own principles of withholding assent that Clitomachus confesses he never knew what his master really thought on any subject.[19] Inethics, 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 onJustice, 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.[citation needed]
All this, however, was nothing but the special application of his general theory, that people did not possess, and never could possess, any criterion oftruth.
Carneades argued that, if there were a criterion, it must exist either inreason (logos), orsensation (aisthêsis), orconception (phantasia). 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.[citation needed]
But after all, people must live and act, and must have some rule ofpractical 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.[20]
^Allen, James."Carneades".Stanford Encyclopedia of Philosophy. Stanford University. Retrieved8 March 2021.Born in Cyrene, then a Greek-speaking city on the Mediterranean coast of North Africa, Carneades pursued his philosophical studies in Athens
^Sharples, R.W. (1995). Honderich, Ted (ed.).The Oxford Companion to Philosophy. Oxford: Oxford University Press. p. 122.ISBN0198661320.Criticizing both Stoic and Epicurean views in the debate on freedom and determinism...
^Sharples, R.W. (1995). Honderich, Ted (ed.).The Oxford Companion to Philosophy. Oxford: Oxford University Press. p. 122.ISBN0198661320.Carneades scandalized Cato the Elder by arguing in favour of justice and against it on successive days
^Allen, James (2006). Borchert, David (ed.).Encyclopedia of Philosophy (2nd ed.). USA: Macmillan Reference. pp. 46–48.ISBN0028657829.Carneades became scholarch of the Academy (Plato's school) sometime before 155BCE, when he was sent to Rome along with the leaders of the Stoa and the Peripatos (Aristotle's school) to represent the interest of Athens before the senate. It was during the embassy to Rome that the most notorious episode in this life took place. According to tradition, Carneades delivered public lectures on succeeding days, defending justice on the first and arguing that it is a form of folly on the second day.
^Barnes, Jonathan (2000).Concise Routledge Encyclopedia of Philosophy. New York: Routledge. p. 124.ISBN0415223644.He was a celebrated figure; and in 155 BC he was sent by Athens to Rome as a political ambassador where he astounded the youth by his rhetorical powers and outraged their elders by his arguments against justice.
^Allen, James (2006). Borchert, David (ed.).Encyclopedia of Philosophy (2nd ed.). USA: Macmillan Reference. pp. 46–48.ISBN0028657829.Like Arcesilaus and Socrates before him, Carneades wrote nothing, but exerted an influence on his students and contemporaries through his teaching and in-person practice of philosophical debate
^Allen, James (2006). Borchert, David (ed.).Encyclopedia of Philosophy (2nd ed.). USA: Macmillan Reference. pp. 46–48.ISBN0028657829.What is known of him depends ultimately on works written by those who were in a position to observe him, especially Cliomachus, his student and, after an interval, successor as head of the Academy.
^Val. Max., VIII,7, ext.., 5: Idem cum Chrysippo disputaturus elleboro se ante purgabat ad expromendum ingenium suum attentius et illius refellendum acrius.