Do the Stoics succeed in showing how people can be morally responsible for some of their actions within the framework of causal determinism?



Keith Seddon




The Stoic teachers exhort their students to pursue the correct moral path. Seneca urges Lucilius to become a philosopher, and to live life as a philosopher, saying,

It is clear to you, I know, Lucilius, that no one can lead a happy life, or even one that is bearable, without the pursuit of wisdom, and that the perfection of wisdom is what makes the happy life, although even the beginning of wisdom makes life bearable.

Seneca, Ep 16.1, trans. Campbell 1969, 63

It would be futile to instruct someone to do something that is known to be impossible. How silly it would be for Stoic teachers to urge their students to exercise their capacity for free will, to choose the correct moral path, if all along it is known that it never is in anyone’s power to do one thing rather than another.


For the Stoics hold that all events throughout the course of history are every one connected to antecedent events that cause them, and that they in turn are themselves antecedent causes of what must follow after. This is the theory of causal determinism. Events occur when they do because they are caused by prior events, and these events were caused to occur when they did by events yet more prior – and so on all the way back to the beginning of the world. And all the way forward to the end of the world. According to this theory, there never has been and there never will be even a single event that is not caused. Everything is how it is, whenever it is how it is, because it has been determined to be like that by prior circumstances that cause it. Events on the thread of time are not like beads on a thread: the first bead may be red, the second blue, and the third green. But the blue bead is not blue because the first one is red, and the green bead is not green because the second bead is blue. Events in time are different. So long as we identify the events correctly, we can say that event B occurs because of event A, and that event C occurs because of event B. Stobaeus tells us that, ‘Zeno says that a cause is “that because of which” … [and] Chrysippus says [also] that a cause is “that because of which” … while that of which it is the cause is “why?”’ (Stobaeus 1.138,14–139,4, in Long and Sedley 1987, 55A)

The entire sequence of causes which stretches out to form the entire history of the world was called by the ancients, fate. Cicero has his speaker say in defence of Stoic theory of divination:

By ‘fate’, I mean what the Greeks call heimarmenê – an ordering and sequence of causes, since it is the connexion of cause to cause which out of itself produces anything. … Consequently nothing has happened which was not going to be, and likewise nothing is going to be of which nature does not contain causes working to bring that very thing about. This makes it intelligible that fate should be, not the ‘fate’ of superstition, but that of physics, an everlasting cause of things – why past things happened, why present things are now happening, and why future things will be.

Cicero, On divination 1.125–6, trans. Long and Sedley 1987, 55L

But if the whole history of the world is exactly and precisely an enormously complex mass of causal threads juxtaposed and interconnected, such that any event and every event embedded in this unimaginably vast nexus must be how it is, where it is, and when it is, how might someone do something different, do A, say, which is morally preferable, rather than B, which is in some measure morally reprehensible? For if the theory of causal determinism is true, no one can ever choose to do A rather than B, or B rather than A. No one ever chooses to do anything. If the Stoic teacher tells the pupil to do A, and they do, this was all along fated to occur. And if they were told to do A, and they do B, then it was this that was all along fated.

If the Stoics are right, and everything is fated to occur just as it does, how can it make sense for them to believe that we are free agents, able to choose what to do, responsible for our own actions, praiseworthy or blameworthy depending on the rightness of our action? Why bother to aim at anything at all? If a certain event A has been fated to occur for all time, why worry about trying to bring A about? It will happen whatever I do. More foolish would be my trying to prevent A. Were I to try, I would fail.


The fatalist can reply that this is not right. Should the theory of causal determinism be true, and should fate thereby be a fact concerning the world, it does not follow that acting is never to any avail. The thought that action is never to any avail is expressed in the ‘Lazy Argument’, and ‘If we gave in to it,’ says Cicero, ‘we would do nothing whatever in life.’

[The argument is posed] as follows: ‘If it is your fate to recover from this illness, you will recover, regardless of whether or not you call the doctor. Likewise, if it is your fate not to recover from this illness, you will not recover, regardless of whether or not you call the doctor. And one or the other is your fate. Therefore it is pointless to call the doctor.’

Cicero, On fate 28, trans. Long and Sedley 1987, 55S

Cicero continues, saying that Chrysippus criticised this argument. Some events are complex and ‘co-fated’. It is false that you will recover from the illness whether or not you call the doctor, because your calling the doctor, and having some treatment, may be the reason why you recover. Calling the doctor, and recovering, are ‘co-fated’. So, to take action certainly can be effective – your calling the doctor resulting in your recovery.

Though seeing this doesn’t to any degree undermine the fatalist’s position, for just as your recovering was fated (if only you had known it), so was your calling the doctor! This might be how it happened, all right, but if the event of your calling the doctor was caused by prior circumstances (as all events are, according to the theory of causal determinism) then in what sense could you be considered to exercise your free will?


Chrysippus employs the example of a cylinder made to roll down a hill (Cicero, On fate 42–3 = Long and Sedley 1987, 62C 8–9; Aulus Gellius, Attic nights 7.2.11 = Long and Sedley 1987, 62D 4). He says that there are two distinct types of cause working here. One is our pushing the cylinder to make it move; this is the ‘auxiliary and proximate cause’ – we can call it the ‘external cause’. And the other is the cylinder’s being round; this is the ‘complete and primary cause’ – which we can call the ‘internal cause’ (see Long and Sedley 1987, 62C 5–6). We may be inclined to object that the being round is not really a cause. It is a property that the cylinder has, as would be its redness and heaviness, just in case it is red and heavy. Chrysippus could reply, and say that whereas the colour and weight of the cylinder have no bearing on its rolling – a blue, light cylinder rolls just as well – its roundness does have a bearing on its rolling: if it weren’t round, it wouldn’t roll. We would say that the roundness was a necessary condition for the cylinder’s rolling, just as the pushing of the cylinder was also necessary: no push, no rolling. But together both the roundness and the pushing were sufficient for the rolling. Chrysippus wants us to note that both the external cause and the internal cause themselves had causes properly located in the causal nexus comprising the entire history of the world. The external cause of the push was itself caused by our foot swinging to meet the cylinder, and the internal cause of the cylinder’s roundness was caused by the manufacturing process that made it. And we may suppose that the rolling will itself cause something else to happen, such as the knocking over of a sheep, or a splash in the stream, or both. In short, nothing has happened which violates the theory of causal determinism.


Next we must apply the logical structure of this example to the case of a human agent. Consider someone who sees a cake on a table. The Stoics talk of perception in terms of ‘assenting’ to an ‘impression’. Having got an impression of a cake, which is to say that the agent’s mind has been causally altered by the cake – just in case there really is a cake on the table, but otherwise causally altered by something else that makes it seem that there is a cake on the table – the agent is ready to ‘assent’ to this impression: which is to say, the agent can say, ‘Yes. It is true that there is a cake on the table.’ For Chrysippus, the impression is like the push given to the cylinder. Just as the push was necessary, but not sufficient, for the cylinder’s rolling, the impression was necessary, but not sufficient, for the agent’s assenting to it. The impression is an external cause. The internal cause of the assent (necessary and with the impression jointly sufficient for the assent) is the agent’s own nature, corresponding to the nature of the cylinder’s roundness. The agent’s nature then, comprises ‘the power of impulse and repulsion, of desire and avoidance – in a word, the power of using impressions’ (Epictetus, Discourses 1.1.12, in Dobbon 1998, 3).

A human agent is not like a billiard ball, which if struck must move off in a certain direction at a certain speed. When ‘struck’ by an impression, the agent can decide what to do, can decide to assent to it, and can decide what to do next. But just as the cylinder’s roundness had antecedent causes so that its being like that fitted in to the overall causal  nexus of fate, so too does the agent’s nature have antecedent causes, these being the agent’s upbringing, attending the classes of a Stoic teacher, and what have you. So again, the theory of causal determinism is unviolated – and it is ‘up to’ the agent, and ‘in their power’ to assent to impressions and to act as they see fit. If this has all been argued correctly, Chrysippus can have his cake and eat it: that is, causal determinism is true, and agents can exercise their free will.

But to what extent is the agent free to form their own nature? If their nature is something that is just imposed on them, how can they be said to be free when this nature determines the outcome of their dealings with circumstance? If through the workings of fate they are exposed to just these experiences, acquire these skills, and develop this particular personality, it would appear to be ‘up to’ fate that they react as they do under the influence of some impression. Internal causes, our own natures, our own dispositions, appear to be locked into and determined in their character by the causal nexus of fate as much as external causes are. Chrysippus is right to draw the distinction between these two kinds of cause, but doing so, and elaborating the distinction, does not help us locate human freedom within a fully determined world.


Would it be better, then, to reject the theory of causal determinism, and to say that at least some events are uncaused, to say that at least some events do not have antecedent conditions, causally necessary and sufficient for their coming about? That is, they just happen anyway. They happen, and there just is no explanation for their happening. This would be to embrace some type of indeterminism. But we can see immediately that this option is unhelpful and probably rather silly. For where do we locate human freedom in such an undetermined, if only partly undetermined, world? Two options may be entertained. Either I reach for the cake, and my action is causally determined by necessary antecedent external causes (my seeing the cake) and by necessary internal causes (my own nature, my predispositions to reach out for something edible in this sort of circumstance) which are jointly sufficient for my acting as I do – or my reaching for the cake is entirely uncaused: my arm just shoots out for no reason at all, my hand grabs the cake, and the next instant that same hand is stuffing the cake into my mouth, all of this for no reason at all, for an uncaused event or action by definition has no explanation of any kind.

Far from allowing freedom to occur, the notion of uncaused events makes my acting to a purpose of my own free will impossible.


We might do better to consider how we experience events on a moment to moment, day by day basis. It certainly seems to us that we are not always caused to act as we do directly by circumstances around us, and it does seem that it is up to us, in some measure at least, as to how we develop and train our inner dispositions – which like the roundness of the cylinder do play an important part in our responding to and dealing with affairs in the world. Indeed, the whole of Stoic moral philosophy has the purpose of bringing our inner dispositions into line with living in such a way as to exhibit moral virtue and living well in the way the Stoics conceive of doing this.

I am not made to eat the cake just because I see it. If I eat the cake, I do so deliberately. I may take time to deliberate about whether or not to eat the cake, or I may not. Either way, my eating the cake is a deliberate act, and what I do deliberately I do freely. Of course there are influences – causal influences – at work here. My feeling hungry, if I do, clearly influences my decision to eat the cake. But this is exactly how I want matters to be. My action only makes sense if these influences are present.


There is one argument that the Stoics may well have offered when confronted with the apparent paradox of human freedom being allowed within the causal nexus of fate. None of the ancient sources express this argument, but since it seems to be implied by and is consistent with their theology, they would have been able to employ it had they wished (see Long 1996, 178–80).

The Stoics identified logos (reason), fate and god, regarding them as different aspects of the one principle which creates and sustains the world (see Diogenes Laertius 7.134–5 = Long and Sedley 1987, 44B and 46B). God, through acting on passive unqualified substance, makes it what it is. But since god is considered to be a body, and is co-extensive with the world and is ‘in’ everything, god must also be in us. The Stoics believed that the governing part of each human soul, the hegemonikon, is a fragment of the divine logos. Epictetus imagines Zeus talking to him: ‘ … I have given you a part of myself, the power of impulse and repulsion, of desire and avoidance – in a word, the power of using impressions.’ (Discourses 1.1.12, trans. Dobbin 1998, 3) Later, he writes:

For if god had so arranged his own part, which he has given to us as a fragment of himself, that it would be hindered or constrained by himself or by anyone else, he would no longer be god, nor would he be caring for us as he ought.

Epictetus, Discourses 1.17.27, trans. Dobbin 1998, 36

It would be wrong, therefore, to regard Stoic fate as being external to agents, as a force that operates upon them. Rather, we should view fate as operating through agents. We are partners with god, working with god to bring about the history of the world as it is meant to be brought about. Should we find ourselves reacting to circumstances in this way rather than that, this is not necessarily fate compelling an outcome that has been predestined behind our backs so to speak; it may be that we ourselves are of our own free volition and in some very small measure, making fate into what it is.


Campbell, Robin. 1969. (trans.) Seneca: Letters from a Stoic. London: Penguin.

Dobbin, Robert F. 1998. (trans. and commentary) Epictetus: Discourses Book I. Clarendon Later Ancient Philosophers. Oxford: Clarendon Press.

Long, A. A. 1986. Hellenistic philosophy: Stoics, Epicureans, Sceptics. 2d ed. Berkeley & Los Angeles: University of California Press.

——— 1996. Freedom and determinism in the Stoic theory of human action. In Problems in Stoicism, ed. A. A. Long, 173–99. London & Atlantic Highlands: Athlone.

Long, A. A. and D. N. Sedley. 1987. The Hellenistic philosophers. Vol. 1. Cambridge: Cambridge University Press.

Sandbach, F. H. 1989. The Stoics. 2d ed. London: Gerald Duckworth.

Sharples, R. W. 1995. Causes and conditions in the Topica and De fato. In Cicero the Philosopher, ed. J. G. F. Powell, 247–71. Oxford: Clarendon Press.

Taylor, Richard. 1992. Metaphysics. 4th ed. Englewood Cliffs: Prentice Hall.

White, Nicholas. 1983. (trans.) Handbook of Epictetus. Indianapolis: Hackett.

© Keith Seddon, Ph.D. 1999


Professor, Department of Philosophy

Faculty of Arts and Humanities

Warnborough University, Canterbury, UK


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Keith Seddon is Director of the Stoic Foundation, an educational trust, offering advice, support and a correspondence course in practical Stoic philosophy to anyone interested in taking up Stoicism as a philosophy to live by. He is also Chairman of the Council of the International Stoic Forum, an online community devoted to discussions of Stoic thought and practice, which may be found at the Yahoo Groups site:


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[Revised 2004-03-24]