Arcesilau

Arcesilaus (c.316–c.240 bc)

Arcesilaus of Pitane came to Athens as a young man, and was seduced by Platonic philosophy. Around 265 he became head of the Academy. He turned the school in a sceptical direction, urging that Plato himself had been of a sceptical bent. He revived the Socratic practice of dialectical argument, in which he displayed remarkable logical skill and honeyed oratorical talent. His dialectical prowess led him to ‘suspend judgment about everything’; but the main target of his arguments was Stoicism, and in particular Stoic epistemology, which he claimed to reduce to incoherence. Recognizing that a sceptic must live and act, he introduced the notion of ‘the reasonable’ as a criterion of sceptical action.

 

1 Life and thought

Arcesilaus was born in Pitane, in north-west Asia Minor. As a youth he was a pupil of the mathematician Autolycus, whom he followed to Sardis. He then travelled to Athens where he studied with Theophrastus. He was destined for a rhetorical career; but his head lay for philosophy. When he removed to the Academy and heard Polemo and Crantor and Crates, he deemed that they were ‘either gods or else remnants of those men of old who were formed from the golden generation’ (Philodemus, History of the Academy XV 5–10). The rest of his life he spent in the Academy. On the death of Crates in c.265 bc he became scholarch, a position he held until his death some twenty-five years later.

He was a celebrated figure, known for caustic wit and also for kindness, for oratorical skill and for the rigour of his argumentation. He wrote epigrams, he enjoyed dalliance and dinner parties – and he was regarded as one of the leading philosophers of the age. But he produced no philosophical writings, and what we learn of his views derives from hearsay: perhaps from first-hand hearsay, for we are told that one of his pupils, Pythodorus, took notes of his lectures.

The Stoic Ariston of Chios , his contemporary, parodied a Homeric verse in describing him as ‘Plato in front, at the back Pyrrho, Diodorus between them’. Homer was describing the chimera, and Ariston insinuates that Arcesilaus was a philosophical monster, a three-fold hybrid.

Arcesilaus began his philosophical life as an orthodox Platonist (see Plato; Platonism, Early and Middle) – we are told that he acquired a copy of Plato’s works as a boy, and that ‘at first when he stated a thesis he argued in accordance with the tradition from Plato and Speusippus up to Polemo’ (Philodemus, History of the Academy XVIII 7–12). He taught a dogmatic Platonism and then became a sceptic.

Later authors spoke of the foundation of a New Academy. But by his own lights Arcesilaus was no innovator – rather, he turned the Academy back to pure Platonism. Not (as some alleged) because he dissembled, secretly teaching unsceptical doctrine, but because (as he argued) Plato himself had been a sceptic. ‘From several of Plato’s books and Socratic dialogues he took the idea that nothing is certain’ (Cicero, The Orator III 67). There are indeed sceptical touches in some of Plato’s works – notably in the early dialogues, which generally end in puzzlement, and in the Theaetetus, which raises and conspicuously fails to answer the question ‘What is knowledge?’ Yet Arcesilaus could read the Platonic corpus and say that ‘in his books nothing is asserted, many issues are argued on both sides, everything is a matter of investigation, nothing certain is said’ (Cicero, Academics I 46).

Diodorus Cronus was celebrated for ‘dialectic’: his philosophical interests were absorbed by logical problems and puzzles. Arcesilaus did not himself engage in logical study – indeed, anecdote has him dismiss dialectic. He took after Diodorus in his practice, inasmuch as he too was renowned for his argumentative ingenuity. He excelled at arguing ‘on both sides of the question’: a proposition (no matter what) is put forward, and first you argue for it and then you argue against it, ‘the arguments on each side being equally powerful’ (Eusebius, Preparation of the Gospel XIV 4.15). The technique finds antecedents in Aristotle’s dialectic. Arcesilaus also harked back to Socrates (§3) and the Socratic elenchos or method of refutation: a thesis (no matter what) is proposed, and you show by arguments which the proposer must accept that it is untenable.

Each of these two techniques demands logical versatility or sophistical sleight of hand. The ancient sources often link them, for if you can argue for and against any proposition then a fortiori you can argue against any thesis, and if you can argue against any thesis whatsoever then you can argue for and against any proposition.

 

2 Scepticism

It is Arcesilaus’ affinities with Pyrrho, the archetypal sceptic of the ancient world, which give him his philosophical bite. ‘He created a new philosophy of non-philosophizing’ (Lactantius, Divine Institutions IV 11), and introduced suspension of judgment and scepticism into the Academy. But even in antiquity, the nature of Arcesilaus’ scepticism was a matter of dispute. According to Numenius (§1), Arcesilaus ‘was a Pyrrhonist in all but the name’ (Eusebius, Preparation of the Gospel XIV 6.6); and a half dozen texts, independent of one another and drawing on early sources, agree that Arcesilaus ‘suspended judgment about everything’: that is to say, he held no beliefs on any subject, and the end of his philosophizing was the eradication of all belief and the introduction of universal suspension of judgment.

Arcesilaus’ logical techniques open a direct route to Pyrrhonism (see Pyrrhonism). If you can produce equally powerful arguments on each side of a proposition, then you will neither believe nor disbelieve that proposition, and if you can produce equally powerful arguments on each side of every proposition, then you will believe no proposition at all. And Arcesilaus had a second route to Pyrrhonism, for he championed akatalēpsia or ‘inapprehensibility’: ‘he denied that there is anything which can be known – not even the one thing which Socrates allowed himself, that he knew that he knew nothing’ (Cicero, Academics I 45). Hence if you have any beliefs, they will be mere opinions. But no one of any sense embraces what he takes to be a mere opinion. Hence no one of any sense will hold any beliefs.

Arcesilaus was a polemicist. He attacked all-comers and exploded any thesis anyone might propose, ‘affirming nothing himself but merely refuting other positions’ (Philodemus, History of the Academy XX 1–4). Such a polemical scepticism is the natural child of the Socratic elenchos, and some scholars have urged that Arcesilaus’ philosophy was essentially a negative and a destructive thing. But polemical scepticism easily fades into Pyrrhonism. For if I refute a thesis which you propound, then I shall not uphold the thesis myself; if I can refute any thesis which is propounded to me, then I shall believe no thesis; and so I shall end up as a Pyrrhonist.

It is sometimes supposed that Arcesilaus always argued ad hominem: if you maintain a certain thesis, then Arcesilaus will show not that the thesis is untenable but that you have no good grounds for maintaining it. It is consistent with a successful ad hominem argument that there are good grounds for holding the thesis, and that Arcesilaus himself holds it on such grounds. Yet the ad hominem approach, universally applied, again fades into Pyrrhonism, for if Arcesilaus can argue ad hominem against all-comers, then in effect he can argue against any thesis.

Much of Arcesilaus’ philosophical activity was directed against the Stoics. Thus he took the Stoic thesis that two stuffs may completely blend or interpenetrate and, relying wholly on ideas which the Stoics themselves maintained, reduced it to absurdity. (He chose a grotesque example: amputate your leg, grind it up, and blend it into the Aegean sea. By the thesis of interpenetration, the leg will blend with every part of the sea and the fleet of King Antigonus will sail through your leg.)

The Stoics held that if you know something, you must have ‘apprehended’ it; that apprehension is assent to an ‘apprehensive appearance’ (phantasia katalēptikē); and that an appearance of something is apprehensive if it is true of that thing, if it was caused by that thing, and if it could not have been produced by anything else (see Stoicism §12). Arcesilaus urged that the third of these conditions could never be met and hence that there are no apprehensive appearances. Hence ‘everything being inapprehensible, it will follow that, for the Stoics too, the Sage suspends judgment’ (Sextus Empiricus, Against the Mathematicians VII 155).

But if Arcesilaus was at his most vigorous against the Stoics, no ancient text suggests that anti-Stoicism exhausted his intellectual parts. The evidence suggests rather that the quarrel with the Stoics was one glamorous episode in his campaign to restore peace and scepticism to the land: the Stoics were the leading ‘dogmatic’ philosophers in town, and any sceptic would feel bound to have a confrontation with them. In any event, the arguments which Arcesilaus used against the Stoics could readily be adapted for use against others: a clever philosopher would not ignore and a combative philosopher would not decline these tempting possibilities. Anti-Stoicism, in other words, soon leaches into a more general ad hominem scepticism and hence, in the end, into Pyrrhonism.

It has often been wondered if Pyrrhonian scepticism is a serious or an interesting philosophical option. One argument which ancient dogmatists deployed against their sceptical colleagues was the following. Human actions are characteristically explained in terms of the beliefs (and the desires) of their agents. But sceptics have no beliefs. Hence sceptics cannot act. Hence sceptics cannot live – the only good sceptic is a dead sceptic.

Arcesilaus was aware of this argument, and had an answer. The argument, he claimed, supposes that three things are necessary for action: before you sink your teeth into the succulent flesh, you must have received an appearance (‘That apple looks ripe’), you must have given your ‘assent’ and formed a belief (‘That apple is ripe’), and you must have had an impulse or desire (you wanted to eat a ripe apple). Arcesilaus demurred:

Two things are necessary for action, an appearance of something appropriate and an impulse towards the appropriate item which has appeared – and neither of these conflicts with suspension of judgement. It is belief, and not appearance or impulse, from which argument separates us.

(Plutarch, Against Colotes 1122C–D)

The apple looks juicy and Arcesilaus wants an apple – so he eats it. No belief intervenes, and none is needed. It is enough to ‘follow the appearances’.

In addition Arcesilaus observed that ‘anyone who suspends judgment about everything will measure his choices and aversions, and in general his actions, by what is reasonable (to eulogon); and if he proceeds in accordance with this standard (kritērion) he will be successful’ (Sextus Empiricus, Against the Mathematicians VII 158). A sceptic will choose to perform those actions which, were they done, could be reasonably defended. Is Arcesilaus here telling us what dogmatists – what Stoics – will be obliged to do, once his arguments have reduced them to scepticism? Or is he reflecting more generally on the way in which any sceptics will make their way through the world? And in the latter case, are his reflections compatible with scepticism – can a sceptic consistently appeal to ‘the reasonable’? To such teasing questions our texts yield no safe answers.