In many ways, Aristotle's ethics provides the form for the adumbration of the ethical teaching of the Hellenistic schools. One must first provide a specification of the goal or end (telos) of living. This may have been thought to provide something like the dust jacket blurb or course description for the competing philosophical systems—which differed radically over how to give the required specification.
A bit of reflection tells us that the goal that we all have is happiness or flourishing (eudaimonia). But what is happiness? The Epicureans' answer was deceptively straightforward: the happy life is the one which is most pleasant. (But their account of what the highest pleasure consists in was not at all straightforward.) Zeno's answer was “a good flow of life” (Arius Didymus, 63A) or “living in agreement,” and Cleanthes clarified that with the formulation that the end was “living in agreement with nature” (Arius Didymus, 63B). Chrysippus amplified this to (among other formulations) “living in accordance with experience of what happens by nature;” later Stoics inadvisably, in response to Academic attacks, substituted such formulations as “the rational selection of the primary things according to nature.” The Stoics' specification of what happiness consists in cannot be adequately understood apart from their views about value and human psychology.
The best way into the thicket of Stoic ethics is through the question of what is good, for all parties agree that possession of what is genuinely good secures a person's happiness. The Stoics claim that whatever is good must benefit its possessor under all circumstances. But there are situations in which it is not to my benefit to be healthy or wealthy. (We may imagine that if I had money I would spend it on heroin which would not benefit me.) Thus, things like money are simply not good, in spite of how nearly everyone speaks, and the Stoics call them ‘indifferents’ (Diog. Laert., 58A)—i.e., neither good nor bad. The only things that are good are the characteristic excellences or virtues of human beings (or of human minds): prudence or wisdom, justice, courage and moderation, and other related qualities. These are the first two of the ‘Stoic paradoxes’ discussed by Cicero in his short work of that title: that only what is noble or fine or morally good (kalon) is good at all, and that the possession (and exercise) of the virtues is both necessary and sufficient for happiness. But the Stoics are not such lovers of paradox that they are willing to say that my preference for wealth over poverty in most circumstances is utterly groundless. They draw a distinction between what is good and things which have value (axia). Some indifferent things, like health or wealth, have value and therefore are to be preferred, even if they are not good, because they are typically appropriate, fitting or suitable (oikeion) for us.
Impulse, as noted above, is a movement of the soul toward an object. Though these movements are subject to the capacity for assent in fully rational creatures, impulse is present in all animate (self-moving) things from the moment of birth. The Stoics argue that the original impulse of ensouled creatures is toward what is appropriate for them, or aids in their self-preservation, and not toward what is pleasurable, as the Epicureans contend. Because the whole of the world is identical with the fully rational creature which is God, each part of it is naturally constituted so that it seeks what is appropriate or suitable to it, just as our own body parts are so constituted as to preserve both themselves and the whole of which they are parts. The Stoic doctrine of the natural attachment to what is appropriate (oikeiôsis) thus provides a foundation in nature for an objective ordering of preferences, at least on a prima facie basis. Other things being equal, it is objectively preferable to have health rather than sickness. The Stoics call things whose preferability is overridden only in very rare circumstances “things according to nature.” As we mature, we discover new things which are according to our natures. As infants perhaps we only recognised that food and warmth are appropriate to us, but since humans are rational, more than these basic necessities are appropriate to us. The Greek term ‘oikeion’ can mean not only what is suitable, but also what is akin to oneself, standing in a natural relation of affection. Thus, my blood relatives are—or least ought to be—oikeioi. It is partly in this sense that we eventually come to the recognition—or at least ought to—that other people, insofar as they are rational, are appropriate to us. Cicero's quotation of Terence's line ‘nothing human is alien to me’ in the context of On Duties I.30 echoes this thought. It is not only other rational creatures that are appropriate to us, but also the perfection of our own rational natures. Because the Stoics identify the moral virtues with knowledge, and thus the perfection of our rational natures, that which is genuinely good is also most appropriate to us. So, if our moral and intellectual development goes as it should, we will progress from valuing food and warmth, to valuing social relations, to valuing moral virtue. Ideally, we'll have the recognition that the value that moral virtue has is of a different order to those things that we were naturally attracted to earlier. We then come to see that virtue is the only good.
Is that all there is to Stoic ethics? Some writers, such as Annas (1993), suppose that Stoic moral philosophy largely floats free of Stoic metaphysics, and especially from Stoic theology. Other writers, such as Cooper (1996, and 2012), suppose that Stoic moral philosophy is intimately intertwined with Stoic metaphysics. The latter reading draws our attention to the fact that the unfolding of God's providential plan is rational (and therefore beneficial) through and through, so that in some sense what will in fact happen to me in accordance with that plan must be appropriate to me, just like food, warmth, and those with whom I have intimate social relations.
When we take the rationality of the world order into consideration, we can begin to understand the Stoic formulations of the goal or end. “Living in agreement with nature” is meant to work at a variety of levels. Since my nature is such that health and wealth are appropriate to me (according to my nature), other things being equal, I ought to choose them. Hence the formulations of the end by later Stoics stress the idea that happiness consists in the rational selection of the things according to nature. But, we must bear in mind an important caveat here. Health and wealth are not the only things which are appropriate to me. So are other rational beings and it would be irrational to choose one thing which is appropriate to me without due consideration of the effect of that choice on other things which are also appropriate to me. This is why the later formulations stress that happiness consists in the rational selection of the things according to nature. But if I am faced with a choice between increasing my wealth (something which is prima facie appropriate to my nature) and preserving someone else's health (which is something appropriate to something which is appropriate to me, i.e. another rational being), which course of action is the rational one? The Stoic response is that it is the one which is ultimately both natural and rational: that is, the one that, so far as I can tell from my experience with what happens in the course of nature (see Chrysippus' formula for the end cited above, 63B), is most in agreement with the unfolding of nature's rational and providential plan. Living in agreement with nature in this sense can even demand that I select things which are not typically appropriate to my nature at all—when that nature is considered in isolation from these particular circumstances. Here Chrysippus' remark about what his foot would will if it were conscious is apposite.
As long as the future is uncertain to me I always hold to those things which are better adapted to obtaining the things in accordance with nature; for God himself has made me disposed to select these. But if I actually knew that I was fated now to be ill, I would even have an impulse to be ill. For my foot too, if it had intelligence, would have an impulse to get muddy. (Epictetus, 58J)
We too, as rational parts of rational nature, ought to choose in accordance with what will in fact happen (provided we can know what that will be, which we rarely can—we are not gods; outcomes are uncertain to us) since this is wholly good and rational: when we cannot know the outcome, we ought to choose in accordance with what is typically or usually nature's purpose, as we can see from experience of what usually does happen in the course of nature. In extreme circumstances, however, a choice, for example, to end our lives by suicide can be in agreement with nature.
So far the emphasis has been on just one component of the Stoic formulation of the goal or end of life: it is the “rational selection of the things according to nature.” The other thing that needs to be stressed is that it is rational selection—not the attainment of—these things which constitutes happiness. (The Stoics mark the distinction between the way we ought to opt for health as opposed to virtue by saying that I select (eklegomai) the preferred indifferent but I choose (hairoûmai) the virtuous action.) Even though the things according to nature have a kind of value (axia) which grounds the rationality of preferring them (other things being equal), this kind of value is still not goodness. From the point of view of happiness, the things according to nature are still indifferent. What matters for our happiness is whether we select them rationally and, as it turns out, this means selecting them in accordance with the virtuous way of regarding them (and virtuous action itself). Surely one motive for this is the rejection of even the limited role that external goods and fortune play in Aristotelian ethics. According to the Peripatetics, the happy life is one in which one exercises one's moral and theoretical virtues. But one can't exercise a moral virtue like liberality (Nic. Eth. IV.1) without having some, even considerable, money. The Stoics, by contrast, claim that so long as I order (and express) my preferences in accordance with my nature and universal nature, I will be virtuous and happy, even if I do not actually get the things I prefer. Though these things are typically appropriate to me, rational choice is even more appropriate or akin to me, and so long as I have that, then I have perfected my nature. The perfection of one's rational nature is the condition of being virtuous and it is exercising this, and this alone, which is good. Since possession of that which is good is sufficient for happiness, virtuous agents are happy even if they do not attain the preferred indifferents they select.
One is tempted to think that this is simply a misuse of the word ‘happiness’ (or would be, if the Stoics had been speaking English). We are inclined to think (and a Greek talking about eudaimonia would arguably be similarly inclined) that happiness has something to do with getting what you want and not merely ordering one's wants rationally regardless of whether they are satisfied. People are also frequently tempted to assimilate the Stoics' position to one (increasingly contested) interpretation of Kant's moral philosophy. On this reading, acting with the right motive is the only thing that is good—but being good in this sense has nothing whatsoever to do with happiness.
With respect to the first point, the Stoic sage typically selects the preferred indifferents and selects them in light of her knowledge of how the world works. There will be times when the circumstances make it rational for her to select something that is (generally speaking) contrary to her nature (e.g., cutting off one's own hand in order to thwart a tyrant). But these circumstances will be rare and the sage will not be oppressed by the additional false beliefs that this act of self-mutilation is a genuinely bad thing: only vice is genuinely bad. For the most part, her knowledge of nature and other people will mean that she attains the things that she selects. Her conditional positive attitude toward them will mean that when circumstances do conspire to bring it about that the object of her selection is not secured, she doesn't care. She only preferred to be wealthy if it was fated for her to be wealthy. These reflections illustrate the way in which the virtuous person is self-sufficient (autarkês) and this seems to be an important component of our intuitive idea of happiness. The person who is genuinely happy lacks nothing and enjoys a kind of independence from the vagaries of fortune. To this extent at least, the Stoics are not just using the word ‘happiness’ for a condition that has nothing at all to do with what we typically mean by it. With respect to the second point, the Stoic sage will never find herself in a situation where she acts contrary to what Kant calls inclination or desire. The only thing she unconditionally wants is to live virtuously. Anything that she conditionally prefers is always subordinate to her conception of the genuine good. Thus, there is no room for a conflict between duty and happiness where the latter is thought of solely in terms of the satisfaction of our desires. Cicero provides an engaging, if not altogether rigorous, discussion of the question of whether virtue is sufficient for happiness in Tusculan Disputations, book V.
How do these general considerations about the goal of living translate into an evaluation of actions? When I perform an action that accords with my nature and for which a good reason can be given, then I perform what the Stoics call (LS) a ‘proper function’ (kathêkon, Arius Didymus, 59B)—something that it “falls to me” to do. It is important to note that non-rational animals and plants perform proper functions as well (Diog. Laert., 59C). This shows how much importance is placed upon the idea of what accords with one's nature or, in another formulation, “activity which is consequential upon a thing's nature.” It also shows the gap between proper functions and morally right actions, for the Stoics, like most contemporary philosophers, think that animals cannot act morally or immorally—let alone plants.
Most proper functions are directed toward securing things which are appropriate to nature. Thus, if I take good care of my body, then this is a proper function. The Stoics divide proper functions into those which do not depend upon circumstances and those that do. Taking care of one's health is among the former, while mutilating oneself is among the latter (Diog. Laert., 59E). It appears that this is an attempt to work out a set of prima facie duties based upon our natures. Other things being equal, looking after one's health is a course of action which accords with one's nature and thus is one for which a good reason can be given. However, there are circumstances in which a better reason can be given for mutilating oneself—for instance, if this is the only way you can prevent Fagin from compelling you to steal for him.
Since both ordinary people and Stoic wise men look after their health except in very extraordinary circumstances, both the sage and the ordinary person perform proper functions. A proper function becomes a fully correct action (katorthôma) only when it is perfected as an action of the specific kind to which it belongs, and so is done virtuously. In the tradition of Socratic moral theory, the Stoics regard virtues like courage and justice, and so on, as knowledge or science within the soul about how to live. Thus a specific virtue like moderation is defined as “the science (epistêmê) of what is to be chosen and what is to be avoided and what is neither of these” (Arius Didymus, 61H). More broadly, virtue is “an expertise (technê) concerned with the whole of life” (Arius Didymus, 61G). Like other forms of knowledge, virtues are characters of the soul's commanding faculty which are firm and unchangeable. The other similarity with Socratic ethics is that the Stoics think that the virtues are really just one state of soul (Plutarch , 61B, C; Arius Didymus, 61D). No one can be moderate without also being just, courageous and prudent as well—moreover, “anyone who does any action in accordance with one does so in accordance with them all” (Plutarch, 61F).
When someone who has any virtue, and therefore all the virtues, performs any proper function, he performs it in accordance with virtue or virtuously (i.e. with all the virtues) and this transforms it into a right action or a perfect function. The connection here between a perfect function and a virtuous one is almost analytic in Greek ethical theorizing. Virtues just are those features which make a thing a good thing of its kind or allow it to perform its function well. So, actions done in accordance with virtue are actions which are done well. The Stoics draw the conclusion from this that the wise (and therefore virtuous) person does everything within the scope of moral action well (Arius Didymus, 61G). This makes it seem far less strange than it might at first appear to say that virtue is sufficient for happiness. Furthermore, because virtue is a kind of knowledge and there is no cognitive state between knowledge and ignorance, those who are not wise do everything equally badly. Strictly speaking, there is no such thing as moral progress for the Stoics (if that means progress within morality), and they give the charming illustration of drowning to make their point: a person an arm's length from the surface is drowning every bit as surely as one who is five hundred fathoms down (Plutarch, 61T). Of course, as the analogy also suggests, it is possible to be closer or farther from finally being able to perform proper functions in this perfected way. In that sense, progress is possible.
We are finally in a position to understand and evaluate the Stoic view on emotions, since it is a consequence of their views on the soul and the good. It is perhaps more accurate to call it the Stoic view of the passions, though this is a somewhat dated term. The passions or pathê are literally ‘things which one undergoes’ and are to be contrasted with actions or things that one does. Thus, the view that one should be ‘apathetic,’ in its original Hellenistic sense, is not the view that you shouldn't care about anything, but rather the view that you should not be psychologically subject to anything—manipulated and moved by it, rather than yourself being actively and positively in command of your reactions and responses to things as they occur or are in prospect. It connotes a kind of complete self-sufficiency. The Stoics distinguish two primary passions: appetite and fear. These arise in relation to what appears to us to be good or bad. They are associated with two other passions: pleasure and distress. These result when we get or fail to avoid the objects of the first two passions. What distinguishes these states of soul from normal impulses is that they are “excessive impulses which are disobedient to reason” (Arius Didymus, 65A). Part of what this means is that one's fear of dogs may not go away with the rational recognition that this blind, 16 year old, 3 legged Yorkshire terrier poses no threat to you. But this is not all. The Stoics call a passion like distress a fresh opinion that something bad is present (Andronicus, 65B): you may have been excitedly delighted when you first saw you'd won the race, but after a while, when the impression of the victory is no longer fresh, you may calm down. Recall that opinion is assent to a false impression. Given the Stoics' view about good and bad, as against merely indifferent things, the only time that one should assent to the impression that something bad is present is when there is something which might threaten one's virtue, for this and this alone is good. Thus all passions involve an element of false value-judgement. But these are false judgements which are inseparable from physiological changes in the pneuma which constitutes one's commanding faculty. The Stoics describe these changes as shrinkings (like fear) or swellings (like delight), and part of the reason that they locate the commanding faculty in the heart (rather than the head, as Plato in the Timaeus and many medical writers did) is that this seems to be where the physical sensations which accompany passions like fear are manifested. Taking note of this point of physiology is surely necessary to give their theory any plausibility. From the inside a value-judgement—even one like “this impending dog bite will be bad”—might often just not feel like such an emotional state as fear. But when the judgement is vivid and so the commanding faculty is undergoing such a change, one can readily enough see that the characteristic sensations might inexorably accompany the judgement.
Another obvious objection to the Stoic theory is that someone who fears, say pigeons, may not think that they are dangerous. We say that she knows rationally that pigeons are harmless but that she has an irrational fear. It might be thought that in such a case, the judgement which the Stoics think is essential to the passion is missing. Here they resort to the idea that a passion is a fluttering of the commanding faculty. At one instant my commanding faculty judges (rightly) that this pigeon is not dangerous, but an instant later assents to the impression that it is and from this assent flows the excessive impulse away from the pigeon which is my fear. This switch of assent occurs repeatedly and rapidly so that it appears that one has the fear without the requisite judgement but in fact you are making it and taking it back during the time you undergo the passion (Plutarch, 65G).
It is important to bear in mind that the Stoics do not think that all impulses are to be done away with. What distinguishes normal impulses or desires from passions is the idea that the latter are excessive and irrational. Galen provides a nice illustration of the difference (65J). Suppose I want to run, or, in Stoic terminology, I have an impulse to run. If I go running down a sharp incline I may be unable to stop or change direction in response to a new impulse. My running is excessive in relation to my initial impulse. Passions are distinguished from normal impulses in much the same way: they have a kind of momentum which carries one beyond the dictates of reason. If, for instance, you are consumed with lust (a passion falling under appetite), you might not do what under other circumstances you yourself would judge to be the sensible thing.
Even in antiquity the Stoics were ridiculed for their views on the passions. Some critics called them the men of stone. But this is not entirely fair, for the Stoics allow that the sage will experience what they call the good feelings (eupatheiai, Diog. Laert. 65F). These include joy, watchfulness and wishing and are distinguished from their negative counterparts (pleasure, fear and appetite) in being well-reasoned and not excessive. Naturally there is no positive counterpart to distress. The species under wishing include kindness, generosity and warmth. A good feeling like kindness is a moderate and reasonable stretching or expansion of the soul presumably prompted by the correct judgement that other rational beings are appropriate to oneself.
Criticisms of the Stoic theory of the passions in antiquity focused on two issues. The first was whether the passions were, in fact, activities of the rational soul. The medical writer and philosopher Galen defended the Platonic account of emotions as a product of an irrational part of the soul. Posidonius, a 1st c. BCE Stoic, also criticised Chrysippus on the psychology of emotions, and developed a position that recognized the influence in the mind of something like Plato's irrational soul-parts. The other opposition to the Stoic doctrine came from philosophers in the Aristotelian tradition. They, like the Stoics, made judgement a component in emotions. But they argued that the happy life required the moderation of the passions, not their complete extinction. Cicero's Tusculan Disputations, books III and IV take up the question of whether it is possible and desirable to rid oneself of the emotions.