Why Physics and Logic are Crucial to Ethics
My friend and former student (at the Stoic School in Rome) Chuck Chakrapani has written a worthwhile article over at the Modern Stoicism site, entitled “Stoic minimalism: stripping the dead bark off orthodox Stoicism.” In it, Chuck pursues a project of updating Stoicism to the 21st century by identifying a set of core notions from ancient Stoicism that can be reformulated in modern day language. It’s the same kind of project that as occupied people like Larry Becker, Bill Irvine, and myself, among several others.
Chuck’s article is long, well written, and cogently argued, and I highly recommended. But (you knew there was a “but” coming, yes?) I think he pushes his minimalism too far. Specifically, Chuck makes two claims that I believe to be incorrect: (i) that of the three classical topoi of Stoicism, “physics,” “logic” and “ethics,” only the latter is necessary for modern Stoicism; and (ii) that Stoic ethics is self-contained and can be derived from first principles.
For instance, concerning point (i) he writes:
“While I have been familiar with Stoicism for decades, I have not read much about Stoic physics and Stoic logic until last year. After studying Stoic physics and Stoic logic more closely last year (Including a full length book on Stoic Physics) I can confidently say my understanding of Stoicism has not increased any more than it did after reading one of the Harry Potter books.”
And concerning point (ii):
“Stoic ethics is a self-contained logical system. For a minimalist, Stoic ethics is a rational, self-contained system that can be built from the first principles and the essence of Stoicism can be found only in Stoic ethics rather [sic] in physics or logic.”
To begin with, I agree with Chuck that we shouldn’t be tied down to whatever the ancient Stoics wrote, with no attempt to improve and update. Stoicism is not a religion, Epictetus wasn’t a god, and the Meditations are not sacred scriptures. Indeed, the ancient Stoics themselves made this point planly clear:
Will I not walk in the footsteps of my predecessors? I will indeed use the ancient road — but if I find another route that is more direct and has fewer ups and downs, I will stake out that one. Those who advanced these doctrines before us are not our masters but our guides. (Seneca, Letters to Lucilius, XXXIII.11)
(i) Why we still need physics and logic
The ancient Stoics built their philosophical system around the study of three “topoi” (areas of inquiry): physics, logic, and ethics. By physics they meant much more than the modern word encompasses, including essentially all the natural sciences, metaphysics, and theology. Physics, in other words, concerned itself with understanding how the world works.
Logic also had a broader meaning than the contemporary one, as it included not just formal logic — at which the Stoics excelled — but also informal reasoning, rhetoric, and even what we would call psychology and cognitive science. Anything that has to do with how to reason well.
Finally, ethics was not as narrowly defined as it is today, to indicate the study of what is right or wrong. Rather, it was the study of how to live a eudaimonic life, a life of fulfilment, or a life worth living.
The Stoics thought that the crucial point was to come to a good understanding of ethics, but that this required a decent grasp of both physics and logic. If we are profoundly mistaken about how the universe works, or if we can’t reason well, then we can hardly expect to figure out how to live a good life. Here is how Diogenes Laertius summarizes various metaphors used by the Stoics to get the point across:
They compare philosophy to an animal, likening logic to the bones and sinews, ethics to the fleshier parts, and physics to the soul. Or again, they liken it to an egg: the outer parts are logic, the next parts are ethics, and the inmost parts are physics; or to a fertile field, of which logic is the surrounding fence, ethics the fruit, and physics the land or the trees. Or to a city that is well fortified and governed according to reason. No part is separate from another, as some of the Stoics say; instead, the parts are blended together. And they used to teach them in combination. (Lives and Opinions of the Eminent Philosophers, VII.40)
Now, Chuck claims that modern Stoicism can (and should) do away with physics and logic and just focus on ethics. He brings forth a number of reasons for it, which I find unconvincing. For instance, he points out that there were some ancient Stoics, like Ariston of Chios, who did just that. This is true, but it only shows that there were differences among the Stoics themselves on how to conceive and implement their philosophy. Like other ancient philosophical schools, Stoicism was characterized by a vibrant intellectual community, with different teachers espousing different, and sometimes novel ideas. For instance, Epictetus — near the end of the Roman period known as the late Stoa — introduced a significantly different type of “role ethics,” which improved on the original version put forth by Panaetius during the middle Stoa. The fact is, though, that Ariston was in the minority among the Stoics, as is clear from reading Diogenes Laertius, among other sources.
Chuck further brings up Posidonius, also from the middle Stoa, and a teacher of Cicero. He is right in reminding us that Posidonius treated ethics as the ultimate goal, but this was no departure from the standard approach: physics and logic had always, from the beginning, been instrumental to ethics, and not regarded as necessary on their own.
A third argument deployed by Chuck for the unimportance of physics and logic is that, allegedly, the Roman Stoics — Seneca, Musonius Rufus, Epictetus, Hierocles, Marcus Aurelius — only did ethics. While it is true that there was a significant shift toward ethics in the Roman period, it is also true that plenty of Roman Stoics still wrote about physics (e.g., Seneca’s Naturales Questiones) and logic. More importantly, we have direct evidence from their writings that they thought the other two topoi to be crucial. Let me give you a couple of examples:
When one of his audience said, ‘Convince me that logic is useful,’ he said, Would you have me demonstrate it? ‘Yes.’ Well, then, must I not use a demonstrative argument? And, when the other agreed, he said, How then shall you know if I impose upon you? And when the man had no answer, he said, You see how you yourself admit that logic is necessary, if without it you are not even able to learn this much — whether it is necessary or not. (Epictetus, Discourses II, 25)
Here Epictetus makes the obvious point that one simply cannot do without logic if one is interested in philosophy. Indeed, Chuck himself built an argument to dismiss physics and logic, but arguments are quintessential applications of logic, and if he didn’t know how to use logic properly he couldn’t even begin to construct the semblance of a reasonable argument.
What the late Stoics did say that both Chuck and I can agree on is that engaging in logic for logic’s sake — what is sometimes derisively called logic chopping — is useless and indeed damaging to the main goal of living a eudaimonic life. Here is Epictetus again:
If I admire the interpretation [of a philosophical treatise], I have turned into a literary critic instead of a philosopher, the only difference being that, instead of Homer, I’m interpreting Chrysippus. (Enchiridion 49)
So, yes, indulging in logic for its own sake is definitely not Stoic, and not even the ancient Stoics — at least those from the late Stoa — would have disagreed. But they most certainly urged their students to study logic and acquire good reasoning skills, and so should we.
What about physics? It too is all over the writings of even the late Stoics. Hierocles’ famous metaphor of the various circles of concern (toward family members, friends, fellow citizens, and humanity at large) is certainly an ethical concept, but it is rooted in the Stoic notion of cosmopolitanism, which in turn is based on a particular view of human beings as social animals capable of reason. The latter comes from physics, and informs the ethics.
Also, consider this:
Every part of me then will be reduced by change into some part of the universe, and that again will change into another part of the universe, and so on forever. (Marcus Aurelius, Meditations V.13)
It’s one of several places in the Meditations were Marcus explicitly uses Stoic physics, and even physical concepts deriving from the Presocratic philosopher Heraclitus, to then derive ethical precepts. In the case of this particular quote, the Heraclitean panta rhei (everything changes), which is a metaphysical principle, is used to alter Marcus’ own ethical conduct, reminding him that he is part of a large dynamic cosmos, and that he should behave accordingly, for instance not resisting change just because it makes him feel uncomfortable.
That said, arguably (see? logic!) the most compelling part of Chuck’s defense of his notion that we should reject Stoic physics and logic is that they are hopelessly out of date with modern physics and logic. But are they, really?
Let’s start with the logic. The Stoics were arguably more advanced than Aristotle in that field, since not only they had arrived at a solid classification of syllogisms that kept medieval logicians busy for more than a millennium, but they had introduced propositional logic, which was the dominant approach in the field up until the late 19th century. The Wiki article on this is pretty good (though a more rigorous and in-depth overview can be found here). The article in part states:
[Propositional logic, aka zeroth-order logic] deals with propositions (which can be true or false) and argument flow. Compound propositions are formed by connecting propositions by logical connectives. The propositions without logical connectives are called atomic propositions. … All the machinery of propositional logic is included in first-order logic and higher-order logics. In this sense, propositional logic is the foundation of first-order logic and higher-order logic.
Bottom line: one does not need anything more than propositional logic to get the job done. So, to learn first and higher-order logics is great if you are a logician, mathematician, or computer scientist. But if your goal is to live a eudaimonic life, so-called zeroth order logic is all you need. And that’s the stuff the ancient Stoics came up with, and that is still valid today.
What about modern physics? Remember that the Stoic term actually includes all the modern natural sciences, metaphysics, and theology. Chuck is correct when he says that a lot of the details, as well as some general ideas, are to be rejected. So far as we know, for instance, the universe is not a living organism, and it is certainly not characterized by a pervasive “pneuma,” the highest form of which is the Logos — the ability of bits and pieces of the universe (i.e., us) to engage in rational thinking.
But major high-level pieces of Stoic physics are still in place, and they are crucial to Stoic ethics. To begin with, the idea that we live in a universe characterized by a complex web of cause and effect. This has direct implications for ethics because it makes Stoics into what modern philosophers call “compatibilists” about free will. What Chrysippus said on the matter still goes.
Moreover, universal cause-effect, coupled with materialism (i.e., the notion that everything that exists is made of some kind of stuff) are both still valid today (they are, after all, the metaphysical foundations of science) and have implications for Stoic ethics: the dichotomy of control would not operate in a metaphysically very different universe, and the Stoic notion that the our minds do not survive death would also be in question. Seneca derives our all attitude toward life from the idea that we are finite beings.
Both Stoic and modern physics and metaphysics tell us that the universe is a dynamic place, with change being the inevitable result of the laws of physics. And we have seen above that this has consequences for Marcus Aurelius’ ethics.
Even the concept of the Logos can actually be modernized to the notion that the universe is, in fact, organized according to rational principles (of unknown origin). This makes it possible for us to comprehend the world, and therefore to navigate it in a virtuous manner (not to mention to do science).
Finally, the famous Stoic injunction to live “according to nature,” a cornerstone of their ethics, is still derived today, as it was more than two millennia ago, from our understanding of human beings as social animals capable of rationality. That, as I mentioned above, is the foundation of Stoic cosmopolitanism, as well as the reason why Epictetus proposed a discipline of (ethical) action along the lines he did.
Bottom line: major parts of Stoic physics are both still valid and they are inextricably connected with the ethics. Major Stoic ethical concepts, from the dichotomy of control to living according to nature, would be floating in mid-air if disconnected from an understanding of Stoic physics.
(ii) Why Stoic ethics is not self-contained and cannot be derived from first principles
By this point it should actually be clear why Chuck’s second assertion is also incorrect. In the first place, his claim that ethics can be derived from first principles is not, alas, accompanied by any mention of such principles. He simply restates the basic axioms of Stoic ethics, without any defense of why one should adopt them instead of any alternative set of axioms, such as the Christian or Buddhist ones. They are most definitely not self-evident, in fact so much so that the Stoics themselves referred to several of their ideas as “paradoxa,” meaning uncommon opinions. So they do require justification, a justification that was provided, in the early Stoas, from physics via logic.
And indeed the relevant connection is precisely what I detailed in the previous section. One needs an understanding of cause-effect, materialism, and especially human nature, in order to arrive at the specific version of ethics proposed by the Stoics. Those connections are still valid and still needed today. Moreover, even if one could somehow do without the physics, just deriving conclusions from a set of axioms requires, you guessed it, logic!
Bottom line: one cannot derive Stoic ethical ideas from first principles, as a minimum understanding of how the world works is necessary. Furthermore, even if one could, one would still need logic to construct the resulting ethical system.
Contra my friend Chuck, therefore — and despite the value of many other aspects of his article — modern Stoicism still has to rely on both physics and logic to get to the ethics. What Zeno of Citium taught is still valid, 24 centuries later.