The Epicureans are a much maligned group. Arguably, they were misunderstood by many of their contemporaries, and there were certainly smeared by the early Christians, who focused on the Epicurean idea that pleasure was the highest good in order to paint them, unfairly, as a bunch of “sex, drugs and rock ‘n’ roll” hedonists. The actual Epicurean position was much more subtle, emphasizing lack of mental distress more than what we moderns call pleasure.

Moreover, the Epicureans distinguished between mental and physical pleasures (with the former being more important, thus foreshadowing John Stuart Mill), and reduced their conception of physical pleasures to a rather minimalist set consisting of the enjoyment of simple foods and the like. Epicureanism was a type of virtue ethics, and therefore put a premium on virtue, maintaining that one cannot attain eudaimonia without it. Nonetheless, the major point of distinction between Stoicism and Epicureanism was precisely that the Stoics considered virtue to be the only intrinsic good, with pleasures (of either the mental or the physical type) classed as preferred indifferents, while the Epicureans in a sense did the reverse, declaring pleasure to be an intrinsic good and virtue a necessary auxiliary, so to speak.

[I call this the Don Robertson test for determining whether you are a Stoic or an Epicurean: when push comes to shove, are you going to be virtuous at the cost of pain, or do you prefer to avoid pain and withdraw from the challenge? If the first, you are a Stoic, if the second, an Epicurean…]

Thinking about these matters, I have recently wondered how the Stoics and the Epicureans would deal with one of the most famous thought experiments in modern philosophy: Robert Nozick’s experience machine. In the following I will first make a few additional comments on Epicurean ethics (we will not discuss their physics or epistemology, among other topics) in order to better contrast it with our ongoing study of Stoicism. I will then introduce Nozick’s scenario and ask how the two schools fare when presented with it. The goal is to add one more argument to the venerable Stoic arsenal of (friendly, of course) criticism of our Epicurean cousins — such as the well known critique by Epictetus in Discourses II.20 (which wasn’t that friendly, come to think of it).

“It is impossible to live a pleasant life without living wisely and well and justly, and it is impossible to live wisely and well and justly without living a pleasant life.” (Epicurus’ Principal Doctrines, translated by R.D. Hicks, 1925)

So back to the Epicurean concept of pleasure. The school distinguished among three types of pleasures: (i) natural and necessary (like eating, drinking, and sleeping), which are easy to satisfy and present no problems for eduaimonia; (ii) natural but not necessary (e.g., erotic pleasure), not difficult to master and not needed for happiness; and (iii) neither natural nor necessary (e.g., luxuries), which we must reject completely.

As you can see, the Epicurean — though not going quite as far as the Cynic — doesn’t exactly subscribe to hedonism in the modern, often derogatory, sense of the term.

Indeed, Epicurus taught to his students the so-called tetrapharmakos (“the four-part cure”), a set of guideline on how to live a eudaimonic existence. Again, the list is enlightening:

Don’t fear god

Don’t worry about death

What is good is easy to get

and What is terrible is easy to endure

(From Philodemus, Herculaneum Papyrus, 1005, 4.9-14)

Epictetus’ criticism of Epicureanism was in part based on a perceive lack of coherence in the rival philosophy, as in the following passage from the above mentioned section of the Discourses:

“So too Epicurus, when he wishes to get rid of the natural fellowship of men with one another, makes use of the very principle of which he is getting rid. For what does he say? ‘Men, be not deceived, be not misled or deluded. There is no natural fellowship of rational beings with one another: believe me. Those who state the contrary deceive you and mislead your reason.’ What concern, then, is it of yours? … Man, why do you take thought for our sake, why do you keep awake for us, why do you light your lamp, why do you rise early, why do you write such big books? … For this is the life of which you pronounce yourself worthy: eating, drinking, copulation, evacuation, and snoring. What does it matter to you, what opinions others will hold on these matters, or whether they are right or wrong? … What, then, was it that roused Epicurus from his slumbers and compelled him to write what he wrote?”

And that last sentence gives me an excellent segue into Nozick’s thought experiment. It is referred to as the experience machine, or sometimes (aptly, in our case!) the pleasure machine, and it is found in Nozick’s 1974 book Anarchy, State, and Utopia. (This machine is not to be confused with the more narrowly pleasurable one imagined by Woody Allen in Sleeper — see top image)

The idea is to consider a machine that could give us whatever desirable or pleasurable experiences we want, something that may actually not be too far into the future, thanks (so to speak) to advancements in virtual reality. Nozick says that the machine would stimulate the brain to induce any experience the subject wishes, and that the user would not be able to distinguish the machine-generated simulation from the real thing. It’s sort of like a Matrix in which you swallowed the blue pill. Nozick then asks whether, given the choice, you would prefer the machine to real life.

He bets that most of us wouldn’t, for three reasons (1974, 43): (a) “It is only because we first want to do the actions that we want the experiences of doing them”; (b) “Someone floating in a tank is an indeterminate blob”; and (c) “There is no actual contact with any deeper reality, though the experience of it can be simulated.” In other words, sensible people (though just how many of those there are around is an empirical question, awaiting social science studies) would reject the blue pill, like Neo does in the Matrix movie, because we want to actually do things (not just experience the feelings of doing them), we want to be a certain type of person (not a simulation of one), and we want to experience an open-ended reality (not a closed, artificial one).

Nozick’s argument can be reconstructed formally (where P means premise and C means conclusion):

P1: If experiencing as much pleasure as possible is what really matters to us, then if we will experience more pleasure by doing X than by doing Y, we have no reason to do Y rather than X.

P2: We will, in fact, experience more pleasure if we plug into the experience machine than if we refuse the offer.

C1: (from P1 and P2) If all that matters to us is that we experience as much pleasure as possible, then we have no reason to reject the offer (i.e., we should enter the machine).

P3: We have reasons (listed above) not to plug into the experience machine.

C2: (from C1 and P3, via modus tollens) Evidently, experiencing as much pleasure as we can is not all that matters to us.

Now, a Stoic would immediately agree with Nozick, for reasons converging on those stated by the modern philosopher. One cannot practice virtue in isolation, outside of a meaningful interaction with other human beings. “Live according to nature,” the Stoic dictum, means to deploy reason to improve social living, because human nature is that of a social animal capable of reason. But inside a virtual reality machine there simply is no such thing as a (real) society, so there is no way to practice virtue. Moreover, since the experience of pleasure and the absence of pain are simply preferred indifferents for the Stoic, the machine has nothing to offer to us. We’d take the red pill.

An Epicurean would not at first troubled by Nozick’s thought experiment either. After all, he could resort to the clause that while pleasure (or, better, lack of pain) is the highest good, eudaimonia nonetheless requires the practice of virtue, as we saw above.

But let us remember that the goal of Epicurean philosophy is to produce happiness via a combination of two states: ataraxia (tranquillity of mind) and aponia (lack of bodily pain). Aponia is why Epicureans — contra the Stoics — withdrew from social and especially political engagement, another major difference between the two philosophies.

Now, regarding ataraxia, Epicurus might have been able to argue that in the world as it actually is one cannot possibly achieve it without the practice of virtue. But Nozick’s machine can offer any kind of experience we want, not just one of straightforward pleasure. So it can also offer the much prized combination of ataraxia and aponia, without the inconvenience of having to practice virtue. If that’s true, and if my understanding of the Epicurean priorities is right, then a follower of Epicurus would indeed accept the blue pill and contentedly live hooked up to the experience machine. A for the rest of us, we need to get back to our chief goal of practicing virtue in the real world, so to make it at least a bit better than how we found it.