He Who Says 'Nothing Can Be Known' Knows Nothing

Opposition to skepticism was key to Epicurus' viewpoint, and placed Epicurus in direct opposition to major aspects of Pyrrho, Plato, and most other leading philosophers of Epicurus' day..

The theory of ideas was rejected as an absurdity by the young Epicurus, because he was a materialist and denied all existences except atoms and space. The theory once rejected, the instrument became useless; scientists have no use for dramatized logic; they depend chiefly upon their senses.

Plato became guilty of another error upon which the sharp-eyed Epicurus did not fail to place a finger. From Pythagoras was inherited the belief in the repeated rebirth or transmigration of souls. Along with this went the belief that the body was a tomb or prison-house, which blurred the vision of reason and prevented perfection of knowledge. All that the human being perceived was the transient appearance of things as opposed to the eternal ideas. This to Epicurus was virtually skepticism.

This error, moreover, was compounded and also aggravated. Closely allied to geometry was the study of astronomy. The latter, in turn, required the observation of heavenly bodies. Thus Plato was in the position of assuming the validity of sensation in the case of the remoter phenomena and denying it in the case of the nearer terrestrial phenomena. This was a glaring inconsistency.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 1.

Epicurus saw the skeptics as issuing a challenge which he needed to meet.

If appeal be made to the historical process, it will become clear that skepticism and dogmatism are also related by the logic of cause and effect. The man who denies the possibility of knowledge is challenging others to declare that knowledge is possible. This challenge had never been seriously taken up before the time of Epicurus, because to speculative thinkers skepticism is merely another way of thinking and escapes notice as a menace or a danger. Neither could this aspect of it have presented itself to Epicurus before he became aware of a passion for the increase of human happiness. This passion once awakened, however, he speedily developed a special acumen for discerning even latent skepticism, as in the teachings of his own Democritus, not to omit those of Plato and Aristotle. His later critiques of preceding philosophies stressed this feature.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 1.

The viewpoint is confirmed by Dr. David Sedley:

In confirmation of this, we can return to the close and apparently conscious parallelism between Epicurus' treatments of determinism and scepticism. The sceptics refuted in Lucretius IV must be, or prominently include, those fourth-century Democriteans like Metrodorus of Chios, Anaxarchus, and even Epicurus' own reviled teacher Nausiphanes, who had played up the sceptical side of Democritus' thought, and against whom Epicurus was eager to marshall the positive empiricist arguments which Democritus had also bequeathed. This scepticism was the result of what I shall call reductionist atomism. Because phenomenal objects and properties seemed to reduce to mere configurations of atoms and void, Democritus was inclined to suppose that the atoms and void were real while the phenomenal objects and properties were no more than arbitrary constructions placed upon them by human cognitive organs. In his more extreme moods Democritus was even inclined to doubt the power of human judgment, since judgment was itself no more than a realignment of atoms in the mind.

Epicurus' response to this is perhaps the least appreciated aspect of his thought. It was to reject reductionist atomism. Almost uniquely among Greek philosophers he arrived at what is nowadays the unreflective assumption of almost anyone with a smattering of science, that there are truths at the microscopic level of elementary particles, and further very different truths at the phenomenal level; that the former must be capable of explaining the latter; but that neither level of description has a monopoly of truth. (The truth that sugar is sweet is not straightforwardly reducible to the truth that it has such and such a molecular structure, even though the latter truth may be required in order to explain the former). By establishing that cognitive scepticism, the direct outcome of reductionist atomism, is self-refuting and untenable in practice, Epicurus justifies his non-reductionist alternative, according to which sensations are true and there are therefore bona fide truths at the phenomenal level accessible through them. The same will apply to the pathe, which Epicurus also held to be veridical. Pleasure, for example, is a direct datum of experience. It is commonly assumed that Epicurus must have equated pleasure with such and such a kind of movement of soul atoms; but although he will have taken it to have some explanation at the atomic level, I know of no evidence that he, any more than most moral philosophers or psychologists, would have held that an adequate analysis of it could be found at that level. Physics are strikingly absent from Epicurus' ethical writings, and it is curious that interpreters are so much readier to import them there than they are when it comes to the moral philosophy of Plato or Aristotle.

• David Sedley, Epicurus' Refutation of Determinism, p. 33.

Anyone who is ridiculous and absurd enough to advocate that "nothing can be known" is taking you for a fool, because he expecting you to accept that he knows that "nothing can be known."

It was indeed excellently said by Epicurus that fortune only in a small degree crosses the wise man’s path, and that his greatest and most important undertakings are executed in accordance with his own design and his own principles, and that no greater pleasure can be reaped from a life which is without end in time, than is reaped from this which we know to have its allotted end. He judged that the logic of your school possesses no efficacy either for the amelioration of life or for the facilitation of debate. He laid the greatest stress on natural science. That branch of knowledge enables us to realize clearly the force of words and the natural conditions of speech and the theory of consistent and contradictory expressions; and when we have learned the constitution of the universe we are relieved of superstition, are emancipated from the dread of death, are not agitated through ignorance of phenomena, from which ignorance, more than any thing else, terrible panics often arise; finally, our characters will also be improved when we have learned what it is that nature craves. Then again if we grasp a firm knowledge of phenomena, and uphold that canon, which almost fell from heaven into human ken, that test to which we are to bring all our judgments concerning things, we shall never succumb to any man’s eloquence and abandon our opinions.

[64] Moreover, unless the constitution of the world is thoroughly understood, we shall by no means be able to justify the verdicts of our senses. Further, our mental perceptions all arise from our sensations; and if these are all to be true, as the system of Epicurus proves to us, then only will cognition and perception become possible. Now those who invalidate sensations and say that perception is altogether impossible, cannot even clear the way for this very argument of theirs when they have thrust the senses aside. Moreover, when cognition and knowledge have been invalidated, every principle concerning the conduct of life and the performance of its business becomes invalidated. So from natural science we borrow courage to withstand the fear of death, and firmness to face superstitious dread, and tranquility of mind, through the removal of ignorance concerning the mysteries of the world, and self-control, arising from the elucidation of the nature of the passions and their different classes, and as I shewed just now, our leader again has established the canon and criterion of knowledge and thus has imparted to us a method for marking off falsehood from truth.

• Cicero, On Ends, Book 1. [63]

Besides, it is only by firmly grasping a well-established scientific system, observing the standard or Canon that has fallen as it were from heaven, so that all men may know it – only by making that Canon the test of all our judgments, that we can hope always to stand fast in our belief, unshaken by the eloquence of any man.

• Torquatus to Cicero, On Ends I.19.63

As for Democritus himself, he committed himself to a certain degree of skepticism when he declared "atoms and void to be the only existences and all else to exist by convention." 45 This, however, was only individual skepticism, which did not prevent him from practicing cheerfulness (euthumia) any more than Pyrrho was prevented from enjoying indifference. To Epicurus, on the contrary, belief or disbelief had become a matter of morals and the happiness of mankind. He was incapable of taking comfort in a negative attitude, as did Democritus and Pyrrho. Thus he was compelled by the inward urge to become a pragmatist as well as a dogmatist and to insist that knowledge must not only be possible but also have relevance to action and to happiness In this matter none of his teachers had set him an example.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 3

In the chapter on the New Physics it will be shown that Epicurus set up Twelve Elementary Principles, which he demonstrated like theorems of geometry, thus classifying himself as a deductive reasoner. The presumption that he was an empiricist has been based in large part upon the zest with which he brandished certain arguments in refutation of the skeptics, who denied the validity of sensation. These arguments are succinctly recorded by Laertius and more amply by Lucretius. The succinct account begins: "Nor does anything exist that can refute the sensations, for neither can a sensation in a given class refute the sensation in the same class, because they are of equal validity, nor can the sensation in a given class refute the sensation in another class, because they are not criteria of the same phenomena." 1 The first limb of this statement has reference to the objection urged by the skeptics that one drinker reports the wine to be sour and another sweet or one bather reports the water to be warm and another cold. The answer of Epicurus was sensible, that the difference was in the observers.2 Neither does the one judgment cancel the other, because each has validity for the observer, nor does the contradiction prove the fallibility of sensation, because the sensation in each instance performs its function as a criterion.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 8.

As cited already, Lucretius used a colorful metaphor to describe those who insist that nothing can be known:

"Again, if any one thinks that nothing is known, he knows not whether that can be known either, since he admits that he knows nothing. Against him then I will refrain from joining issue, who plants himself with his head in the place of his feet. And yet were I to grant that he knows this too, yet I would ask this one question; since he has never before seen any truth in things, whence does he know what is knowing, and not knowing each in turn, what thing has begotten the concept of the true and the false, what thing has proved that the doubtful differs from the certain?

• Lucretius 4:469 (Bailey)

David Sedley interprets this as accusing skeptics of "turning somersaults":

As Burnyeat has beautifully demonstrated, there is a close parallel at the start of Lucretius' anti-sceptic argument, where the sceptic who claims that nothing is known is a man who (IV 472) «has stood with his own head where his feet belong» - clearly Lucretius' imaginative rendering of 1tEP~XcX~W P&1tE~(x. 24 Indeed, 'turn a somersault' could conceivably be the metaphor underlying Epicurus' choice of term. In both passages it is a pragmatic self-refutation that is envisaged.

• David Sedley, Epicurus' Rejection of Determinism - p. 26

The next stage of the argument runs from 38 to 59. Once again it has a close paralle in Lucretius, who at IV 473-7 says of the sceptic, «Given that he has never before seen anything true in the world, how does he know what knowing and not knowing are? What created his preconception of true and false, and what proved to him that the doubtful differs from the certain?». Here we have an appeal to the two closely related standards of preconception (1tp6All4>~, Lucretius' notitia) and word meaning. The sceptic's ability to use the words 'know' and 'not know' significandy presupposes that he possesses the preconceptions of 'true' and 'false,' 'doubtful' and 'certain', since 'true' and 'certain' feature in the definition of 'know'. This conflicts with his claim to have had no experience of truth and certainty, for without that experience he could not have acquired the pre-conceptions.

• David Sedley, Epicurus' Rejection of Determinism - p. 27

The institution of the Canon reflects a contemporary striving for an increase of precision in all the arts, sculpture, architecture, music, and mathematics, but the immediate provocation is to be found in the teachings of Pyrrho the skeptic and of Plato. Pyrrho's rejection of both reason and the sensations as criteria rendered acute the need of establishing a canon of truth. In the judgment of Epicurus Plato also ranked as a skeptic, because he belittled the sensations as undependable and phenomena as deceptive, the only real and eternal existences being the ideas. Thus in his system reason became the only contact between man and reality, and human reason was crippled by the imprisonment of the soul in the body.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 7

The problem of skepticism is attacked disjunctively in the Authorized Doctrines: either all sensations are rejected as valid evidence or some are admitted and some rejected. The former procedure is dealt with in Doctrine 23: "If you are going to make war on all the sensations, you will not even have a standard by reference to which you shall judge those of them which you say are deceptive." This makes it plain once more that not all sensations are true but the validity of some must be checked by the evidence of others.

The Doctrine above is directed at the outright skeptics. The second limb of the disjunctive approach deals with the Platonists, who rejected terrestrial phenomena as deceptive while accepting the evidences of celestial phenomena. Epicurus denied "clear vision (phantasia) from distances," if only the text be not emended.22 He wrongly insisted that heavenly phenomena could be explained from the terrestrial. This betrayed him into committing his most notorious blunder; for the reason that the magnitude of a fire does not seem to diminish with distance as does that of concrete objects he declared the sun to be no larger or only a little larger than it appears to be.23 This ridiculous judgment calls for no comment, but it may be mentioned that Plato's belief in astral gods, however grandiose, is no more acceptable. Epicurus not only censured Plato for accepting the evidence of celestial phenomena while rejecting that of terrestrial phenomena but also condemns him as a mythologer: "Whenever a man admits one phenomenon and rejects another equally compatible with the phenomenon in question, it is manifest that he takes leave of all scientific study of nature and takes refuge in mythology." 2i Hostility to Plato was combined in this case with contempt of mythology.

Nevertheless Doctrine 23 throws light upon the working of the mind in respect of the criteria. Mental activity may be automatic or volitional. It is the automatic mind that errs; it may judge the distant tower to be round; this is the error of "opinion." The discreet observer knows the distant view to be deceptive and suspends judgment until the tower is observed at close hand. A tentative judgment is then confirmed or disproved.25 In the case of the size of the sun, which is visible but never at close hand, the judgment held good, as Epicurus believed, because not contradicted.

The sensations are consistently regarded as witnesses in court.28 Their evidence may be false, as in the case of the oar half-immersed in the water, which appears to be bent. False evidence is to be corrected by that of other sensations. The evidence of all witnesses must receive attention. The volitional mind, as opposed to the automatic mind, which errs, functions as judge.

By way of concluding this account of the Sensations as criteria it is well to present a synoptic view of the evidence. Nowhere in our extant Little Epitome or the Authorized Doctrines do we find the statement "that all sensations are true." On the contrary, the Epitome begins by urging the student "to give heed to the sensations under all circumstances and especially the immediate perceptions whether of the intelligence or of any criterion whatsoever," which manifestly allows some value to all sensations and special value to immediate sensations.27 At the end of the Epitome the student is warned to check his own observations by those of others.28 These authentic statements are incompatible with belief in the infallibility of sensation. They presume belief in gradations of value among sensations and also the need of perpetual caution against error.

Of three Authorized Doctrines devoted to the topic, 23, 24, and 25, the first urges attention to "all the clear evidence"; the second warns that the rejection of all the sensations leaves the observer without the means of checking sensation by sensation; the third warns of the confusion resulting from rejecting any particular sensation. All of these are of the nature of warnings and completely belie the reckless verdict of an otherwise meticulous scholar "that the Epicureans boldly said that every impression of sense is true and trustworthy." 29

Lastly, in every instance above mentioned the word for sensation is aisthesis and not phantasia. That somewhere Epicurus had actually written "all phantasias are true" seems certain; in which of his writings it is unknown, but the evidence is sufficient.30 This statement, as being assailable, was pounced upon by his detractors and zealously ventilated. If, however, the extant texts of Epicurus be taken as a guide, the phantasia or "fantastic" perception is merely the highest grade of evidence; the aisthesis, the perception of particulars, is the criterion.

• Norman DeWitt, Epicurus and His Philosophy, Chapter 8

This task was undertaken by Epicurus' young contemporary Colotes, whose book, On the point that it is not possible even to live according to the doctrines oj the other philosophers (1tEpt 'tOU on X:Cl'to. 'to. 'trov CiAArov cptAoaocprov bOyJ.1Cl'tCl OUbE ~i\v tanv, Adv. Col. 1107E), developed a new battery of anti-skeptical strategies for use against Arcesilaus, strategies which he turned against some of his dogmatic opponents as well. Colotes' book so offended Plutarch four hundred years later that he composed two treatises in reply, the first of which, Against Colotes, provides all of our named testi- mony concerning Colotes' arguments.

…

It is also difficult to ascertain what Colotes~ motives were in se- lecting the philosophers and schools he chose to include in his book. Beginning with Democritus, who takes pride of place as the father of atomism, and concluding with certain unnamed contem- poraries whom Plutarch identifies as the Cyrenaics and the Aca- demic followers of Arcesilaus, who suspend assent on all matters (oi 7tEpi 7teXv'tcov £7t£XOV'tEC;, Adv.Col. 112(k;-D), Colotes attacks in chronological order Parmenides, Empedocles, Socrates, Melissus, Plato, and StilpO.13 It is often supposed that Colotes attacks philoso- phers other than Arcesilaus (whom he never explicitly names: lac. cit.) simply because they had been claimed as authorities by the skeptical Academy, but this view cannot stand without substantial q ualification. 14 In the first place, the list of philosophers whom Co- lotes attacks does not correspond exactly to any list of Academic authorities. Secondly, Colotes makes no mention of Pyrrho,15 an omission that is most difficult to explain if, as some contemporaries thought (Ariston of Chios and Timon: D.L. 4.31£), he importantly influenced Arcesilaus' philosophical development.

did not consider Pyrrho a precursor of Academic skepticism, or he is not attacking Arcesilaus' authorities. Thirdly, it is unlikely that Ar- cesilaus would have claimed Stilpo or Colotes' other contemporary opponents, the Cyrenaics, as authorities to establish a pedigree for his advocacy of epoehe. Finally, since Colotes' purpose is to show (as his title announces) that it is impossible to live according to the doctrines of the other philosophers, he has no reason to restrict his attack to Arcesilaus and his acknowledged authorities.

What is striking in the list of Colotes' opponents is that all of them somehow reject the Epicurean tenet that all impressions are true (ef n.37 infra). I suggest that Colotes' purpose is to discredit those opponents who cast doubt upon the plain evidence of the senses, regardless of whether Arcesilaus claimed them as authorities for his skepticism. If this is so, we can easily see why Colotes discusses figures like Stilpo or the Cyrenaics, who cannot plausibly have been claimed as authorities by Arcesilaus, but who did cast doubt on the evidence of the senses, and why he takes no account of the Stoics or Peripatetics, the contemporary schools whose epistemol- ogy was least likely to be accounted skeptical. It is far more likely that Colotes attacked such comparatively minor figures as Stilpo and the Cyrenaics because Epicurus had already put them on the roster of the school's rivals, 17 than that Colotes sought to discredit them as skeptical authorities. Of course, Colotes may well have considered Arcesilaus his most important opponent: Colotes is re- ported to have been most annoyed by his reputation (Adv.Col. 1121E), he puts him last in his book, and his attack on Socrates, I shall argue, certainly is intended to discredit Arcesilaus' use of him as an authority for epoehe. 18

What featured prominently in Stoic attacks on Arcesilaus, that universal epoche actually makes it impossible to live. Colotes naturally modifies this apraxia argument (a version of which Epicurus had already used against the ethical determinist in On Nature) to serve Epicurean rather than Stoic epistemology, and against opponent after opponent he argues that to deny the truth of all impressions is to abolish knowledge, and that without knowledge life becomes im- possible.19 In putting his case, Colotes is given to rather graphic illus- trations: of Arcesilaus, for instance, he asks, "how is it that the man who suspends judgment does not go running off to a mountain instead of to the bath, or why does he not get up and walk to the wall instead of the door when he wishes to go out to the agora?" (Adv. Col. 1122E; discussed 262ff infra). This colorful polemic well serves Colotes' rhetorical purpose of discrediting his opponents by making them appear ridiculous. The alleged inconsistency between an opponent's views and conduct was a common argumentative strategy in Hellenistic philosophy, one especially useful in silencing him in public debate. Colotes characterized the doctrine of epoche as bait for bold and flighty youth (Adv.Col. 1124B), and no doubt sought to turn the tables against Arcesilaus by discrediting epoche through its inconsistency with living. But his apraxia argument, as we shall see in detail in the next section, does pose a serious chal- lenge to the Academic to show how universal epoche is consistent with the requirements of life itself.

Van der Waerdt - Colotes and the Epicurean Refutation of Skepticism

Can we come to a reliable understanding of this position, or any other position, without having read everything that remains from the ancient philosophical texts? Yes, to an extent we can. We have to if we want to live the best life possible to us! And that is in part why the Epicurean criticized Socrates for not being honest with his students and from the beginning telling them exactly what he thought about a question.

Cicero in Academica II iii Lucullus:

Nor is there any difference between ourselves and those who think that they have positive knowledge except that they have no doubt that their tenets are true, whereas we hold many doctrines as probable, which we can easily act upon but can scarcely advance as certain ; yet we are more free and untrammeled in that we possess our power of judgement uncurtailed, and are bound by no compulsion to support all the dogmas laid down for us almost as edicts by certain masters. For all other people in the first place are held in close bondage placed upon them before they were able to judge what doctrine was the best, and secondly they form judgments about matters as to which they know nothing at the most incompetent period of life, either under the guidance of some friend or under the influence of a single harangue from the first lecturer that they attended, and cling as to a rock to whatever theory they are carried to by stress of weather. For as to their assertion that the teacher whom they judge to have been a wise man commands their absolute trust, I would agree to this if to make that judgement could actually have lain within the power of unlearned novices (for to decide who is a wise man seems to be a task that specially requires a wise man to undertake it) ; but granting that it lay within their power, it was only possible for them after hearing all the facts and ascertaining the views of all the other schools as well, whereas they gave their verdict after a single hearing of the case, and enrolled themselves under the authority of a single master. But somehow or other most men prefer to go wrong, and to defend tooth and nail the system for which they have come to feel an affection, rather than to lay aside obstinacy and seek for the doctrine that is most consistent.