Epicureanism Page 10
Stoic criticisms of Epicurus
Chrysippus (c.280–206 BCE), the third head of the Stoic school, attacks Epicurus from the opposite direction in his reply to the lazy argument. He shows that causal determinism does not make the future inevitable in a manner that renders action or deliberation futile (Fat. 30). The Stoics believe that every event is both causally determined and fated. Every event occurs in accordance with god’s providential plan, because god sets up the causal structure of the cosmos so that events unwind exactly as ordained in his plan. The Stoics wish to show that such a thoroughgoing determinism is compatible with human agency.
Let us return to my skin cancer. Chrysippus says that certain events are “co-fated”: for instance, it is fated (and causally determined) both that I will recover from the cancer and that I will seek treatment; it is through my fated action of seeking treatment that my fated recovery will occur (Fat. 30). So if I am stricken by a skin cancer, and it is causally determined that I will not die as a result of the cancer, it does not follow that going to the doctor to get the cancer treated is pointless, since it is my action of going to the doctor and getting it treated that will bring about my recovery, instead of having the untreated melanoma metastasize and kill me. All that is needed for actions to have a point is that they be causally efficacious, so that statements of the following sort are true: “If you seek treatment, you will not be killed by the melanoma, and if you do not, you will be killed”.
For many of our actions, I think that we can believe that what we are going to do is causally determined, and we can even know what action we will take (so “self-foreknowledge” is not a bar to acting), without rendering that action pointless or our deciding to act as we do irrational. For instance, if I am diagnosed with cancer and am told of the treatment options, I may perfectly well know exactly what I am going to do (I will get it removed), and I may believe that this action of mine is causally determined by my brain states that realize my beliefs about the cancer, my desire not to die young and so on. None of this would have any impact on the rationality of seeking treatment.
So if Chrysippus is right, it seems that Epicurus had no reason to fear determinism, and no reason to posit the swerve. He could have happily accepted Democritus’ view that new motion always arises out of old, in an endless chain of causation, and that what will occur has already been set for ages, without needing to deny that what we do as agents has an impact on the world.
PART II
Epistemology: introduction and overview
Can we gain knowledge of the world? And if so, how do we gain knowledge of the world? These are two of the central questions asked in the branch of philosophy currently called “epistemology”, or the theory of knowledge. The Epicureans themselves call this part of their philosophy “canonic”, derived from the Greek word kanōn, or yardstick, and it is concerned with setting out the criteria of truth. The Epicureans are resolutely empiricist, with all of our concepts and knowledge ultimately being derived from the senses. Since the simple observation that there are bodies in motion serves as the linchpin of their physics, they must secure the reliability of the senses against sceptical attack. They do so, trying to show that scepticism is self-refuting. But scepticism is not merely theoretically unpalatable, it is unliveable (Chapter 9).
The three criteria of truth are sensations, “preconceptions” and feeling (DL X 31). The Epicureans set out their “canonic” with their physics (DL X 30). And for good reason: Epicurean epistemology is closely related to their psychology, which they understand as a branch of physics, the study of nature. They give an analysis of sensation as a purely passive reception of impressions from the environment, and they make the startling claim that all of these sensations are true. Repeated sensations give rise to “preconceptions”, or basic concepts, and further concepts are generated by psychological operations on these basic concepts. With these two criteria, we are able to confirm or disconfirm particular judgements about the world as well as physical theories (Chapter 10).
Since feelings of pleasure and pain are the criteria of choice and avoidance (DL X 34), we shall deal with that part of the canon when we turn to Epicurean ethics.
NINE
Scepticism
A pattern of argument ubiquitous in Epicureanism is to start from something evident in sensation and on its basis infer a conclusion about realities hidden from direct observation. So, for example, Epicurus takes the obvious phenomenon of bodily motion to establish the existence of unobservable void. But predecessors of Epicurus such as Parmenides and Democritus, and successors of his, such as the Academic and Pyrrhonian Sceptics, marshalled powerful arguments against the reliability of the senses.
The Epicureans think that such a sceptical view of the senses is untenable. Before we look in Chapter 10 at the Epicureans’ positive epistemology, we shall first examine their anti-sceptical arguments. That is because one of the primary Epicurean strategies for supporting their positive epistemology is to try to show that all other alternatives to their own views have untenable sceptical consequences. The Epicureans give three major anti-sceptical arguments. The first is that scepticism is self-refuting. The second is that the sceptic (qua sceptic) cannot have knowledge of the concepts needed to formulate the sceptical position. The third is that scepticism is unlivable.
Unfortunately, we do not have any extended Epicurean expositions of these arguments. However, Lucretius does briefly state each (DRN IV 469–99, IG 1–27, LS 16A). Epicurus himself probably formulated these arguments against philosophers such as Parmenides and Democritus, who cast doubt on whether the senses were reliable. However, his younger compatriot Colotes extended the attack to Arcesilaus, who assumed the leadership of the Academy and turned it in a sceptical direction around the time of Epicurus’ death. Arcesilaus argued that there are no sense-impressions that we cannot be mistaken about. As a result, we cannot gain knowledge, and we should suspend judgement. Centuries later, the Pyrrhonian Sceptic Sextus Empiricus asserted that the Academics were themselves dogmatists of a sort, in so far as they hold that knowledge is impossible, whereas the proper sceptic suspends judgement even on that question (Pyr. 11–5,1 226). Both the Academic and Pyrrhonian Sceptics were well aware of the sorts of anti-sceptical arguments put forward by the Epicureans and responded to them. We shall look at these responses, in order to help highlight the philosophical issues raised by the Epicurean arguments.
The argument from self-refutation
The first argument is quite simple: if somebody thinks that nothing can be known, it follows from his position that he cannot know that nothing can be known. So there is no point in arguing with that person, as his position is self-refuting (DRN IV 469–72).
We need to be careful here. The statement “nothing can be known” is not self-contradictory, unlike the statement “this sentence is false”. Lucretius’ claim is that the position that nothing can be known cannot be consistently endorsed. If I am a dogmatist and claim that we can attain knowledge, and my sceptical interlocutor claims that I am wrong and states “I know that nothing can be known”, he has immediately refuted himself. A sceptic putting his position forward for debate must immediately concede defeat, and in this sense his position is self-refuting.1
Any cautious sceptic, of course, will avoid claiming to know that he knows nothing, unless he enjoys paradox-mongering. One strategy for avoiding self-refutation, endorsed by the Academic Sceptic Cicero, softens the degree of commitment to the sceptical position. Perhaps I cannot consistently know that knowledge is impossible. Still, I note the ways in which sensations often are deceptive, I take into account our inability to discover any reliable criterion for distinguishing true from false sensations, and I ponder the endless philosophical disputes over matters such as the existence of the gods and the good life for human beings. Given these facts, it is at least plausible to suppose that knowledge is impossible. And “it’s plausible to suppose that knowledge is impossible” is not self-refuting (Acad. II 109–10).
Still, Lucretius could try to reinstate his basic objection. If we gloss “it’s plausible to suppose that p” as “I have good reason for believing p” or “I am justified in believing p“, then Cicero’s position becomes “I am justified in believing that knowledge is impossible”. And then, as the statement “I am justified in believing that no beliefs are justified” is self-refuting, Lucretius could press the Academic Sceptic to spell out his grounds for thinking he can have justified beliefs while at the same time believing that knowledge is impossible.
The second sceptical strategy for avoiding self-refutation is quite different. The Pyrrhonian Sceptic Sextus Empiricus says that scepticism is not a doctrine, but a skill and a way of life (Pyr. 18–11). The sceptic suspends judgement on all questions, including whether knowledge is possible. And because the sceptic has no sceptical doctrine, he does not have a self-refuting doctrine. Instead, what makes him a sceptic is that he has a knack for going around and producing suspension of judgement in himself and in others. So if I am an Epicurean he will present me with examples of apparent design in order to shake my confidence that the gods have nothing to do with the administration of the world and to cause me to have no opinion one way or the other on the topic, and likewise with my other pieces of self-assured dogma. He will have a toolbox of opposing arguments, many of them furnished by various dogmatic philosophers, ready at hand to whip out as need be. But these arguments are all dialectical – they are all aimed at me, proceeding from premises I accept or can be brought to accept – and the sceptic himself is not committed to any of their premises or conclusions.
This strategy seems to sidestep successfully the charge of self-refutation, although the Epicurean could try to claim that the sceptic has, at least implicitly, a sceptical position presupposed by his practice, one that can be dragged out into the light and examined for possible self-refutation. But as far as responding to the Pyrrhonian practice itself, the Epicurean would simply deal with the arguments as they come. For instance, they would argue that the putative pieces of godly beneficence, such as Socrates’ observation in his version of the argument from design (Xen. Mem. 1.4.2–7) that the gods kindly put the anus far from the nose, give us little reason to believe in the existence of beneficent deities when weighed against the horrific suffering and manifest flaws in the world.
The argument from concept-formation
After giving the self-refutation argument, Lucretius states that the sceptic must also have knowledge in order even to formulate his position: knowledge of the meanings of his terms. In order to state “nothing can be known” and to give his arguments in support of the position, he will have to understand the meanings of terms such as “knowledge”, “true”, “false” and “doubtful” (DRN IV 473–7). So the act of stating the sceptical position demonstrates that it is false. And even in the case of the Pyrrhonian, who claims to have no position, Lucretius’ argument could be applied: in engaging in his sceptical activity, the Pyrrhonian shows that he knows a great number of things, by his understanding of the terms of the arguments he proffers.
In theory, the sceptic strongly committed to the dialectical nature of his argumentative practice could reply that he does not claim to understand what he is talking about, that he is simply moving about the dogmatists’ own terms in the way that they use them, and it is entirely on the dogmatist to make what he will of the sceptics’ utterances. Prudently, Sextus does not go this route. Instead, he restricts the scope of his scepticism. The sceptic suspends judgement on the way things are in the world, and suspending judgement on these matters does not preclude him from making statements about how things appear to him (Pyr. I 13–15). In the case of concepts, the sceptic understands perfectly well what the Epicurean means by terms such as “body” and “atom”, so he knows what the thesis “the mind is composed of atoms” means. But he suspends judgement on questions such as whether there are bodies and atoms in the world, and whether the mind is made of atoms or is incorporeal (Pyr. II 10–11).
Lucretius thinks, however, that the sceptic who casts doubt on the reliability of the senses cannot consistently avail himself of knowledge of concepts. As we shall see, the Epicureans have an empiricist account of concept-formation. For instance, I get basic concepts such as “cow” from having repeated sense-impressions of cows, caused by cows in my environment, and other non-basic concepts are formed by combining, augmenting and transposing these basic concepts. So, writes Lucretius, if scepticism were true – if we were unable to gain knowledge of the way the world is via our sensory interactions with the world – we would never have gained an understanding of concepts such as “true”, as they have their origin in the senses (DRN IV 478–9). So in stating his position the sceptic shows us not only his knowledge of the meanings of his words but also the way in which our senses get us in touch with the world.
The sceptic would probably reject this argument as question-begging: Lucretius is already presupposing the reliability of the senses and that our basic concepts map onto the world, which is the very question at issue. Sextus writes that the sceptic “apprehends” the dogmatists’ terms in the sense of understanding them, but he does not presuppose that these concepts arise from our senses interacting with that sort of object. Sextus adds that the dogmatist should not presuppose this either, as otherwise it would be impossible to enquire whether any X (e.g. god) exists without already presupposing that the object of your enquiry exists (Pyr. II 1–9).
The inaction argument
The final Epicurean objection to scepticism is the classic “inaction” (apraxia) argument, sometimes called the “lazy” argument. We saw earlier (Ch. 8, § “‘Effective agency’ and the pinciple of bivalence”) how the Epicureans advance an argument of this sort against the principle of bivalence, asserting that to believe that truths about the future were settled since time immemorial would render action pointless. Similarly, scepticism would undercut the basis for any action. Lucretius writes that if you lose confidence in the trustworthiness of the senses, life would collapse, as you would have no reason to do things such as avoid cliffs and other hazards (DRN IV 500–510). After all, if the senses were unreliable, then the mere fact that it looks as though there is a cliff ahead would give me no reason to believe that there is a cliff ahead. And likewise, if the senses were unreliable, even if there is a cliff ahead, I would have no reason to suppose that if I walk off the cliff I shall fall down and dash my brains out on the rocks below, as that belief is founded on my observing that that is what has happened. The practical consequences of scepticism are illustrated by the amusing (although almost certainly apocryphal) stories told about the sceptic Pyrrho, after whom the Pyrrhonists named themselves, who was able to survive only because his friends were constantly pulling him back from cliff edges and out of the way of speeding carts (DL IX 62).
Initially, this argument appears invalid. After all, from the premise “believing p would make life unlivable”, it does not follow that “not-p”. At best, the argument would seem to show that scepticism regarding the senses is pragmatically unacceptable, not that it is false. We could try to make the argument valid by changing the premise slightly: people are able to use their senses to navigate around the world successfully and live their lives, and they would be unable to do so if the senses were unreliable. But put in this way, the argument appears question-begging: after all, we know that people can use their senses to navigate around the world successfully because we see that they do so. In any case, ancient sceptics did not question the apraxia argument in either of these ways, probably because ancient philosophies were supposed to be ways of life, not just theoretical positions. Instead, they try to show how one can live as a sceptic, so that scepticism does not have disastrous practical consequences.
The first sort of reply, once again, is offered by an Academic Sceptic. The sceptic who eschews claims of knowledge can still guide his life by the more modest criterion of the plausible. I may not know that there is a cliff ahead, that the door is a better wa
y of exiting the classroom than the window, or that a peanut butter sandwich is a better meal than a handful of tacks, but all of these are highly plausible (Acad. II 103–4, LS 69I). Indeed, we need not confine ourselves to the plausibility of individual sense-impressions. The Academic Sceptic Carneades, from whom Cicero derives his notion of the “plausible” impression, devises an elaborate system for testing impressions. In important matters, we can investigate a plausible impression further and see whether it is corroborated by further impressions and whether it coheres with them. It looks like there is a snake ahead in the house, but further impressions could be of a snake or just a coiled rope, and a host of past impressions may help reinforce (or undercut) the plausibility of there being a snake in this house, in this climate (Sext. Emp. Math. VII 166–84, IG III-18, LS 69D-E).
The Epicurean would probably home in on the notion of “plausibility”. Is “plausible” here no more than a measure of subjective convincingness? After all, the mere fact that something is highly plausible to me need not guarantee that it is true, a point that Carneades and Cicero themselves, as sceptics who eschew claims to knowledge, insist on. If so, then the plausibility of some impression gives me no reason to believe that it is true, that it reflects the way the world is, and then I have no reason to believe that acting on the basis of what is plausible is more likely to be successful than any other course of action. On the other hand, if sceptics believe that plausible impressions are more likely to be true than not, the Epicureans will ask what grounds the sceptic has, as a sceptic who believes knowledge is impossible, for this confidence.2