Dorothea Frede’s chapter in The Cambridge Companion to the Stoics is about determinism, and it’s a must read for anyone seriously interested in the philosophy of Stoicism.
Frede’s approach is to contrast the Stoics with Aristotle, because the two schools share a number of positions, and yet differ markedly in certain crucial respects. The idea is that it is easier to appreciate the differences if one also has an understanding of the similarities.
Aristotle and the Stoics agreed that the universe is finite; that physical nature is a continuum of matter, space and time; they agree on “contingency,” meaning that some things or states are neither necessary nor impossible; there is no motion without a cause, and given the same circumstances one gets the same outcome.
Here is where the two approaches diverge: the Stoics focused on the physical constitution of bodies and their interaction, not on substances and their properties, like Aristotle did; instead of Aristotle’s famous four causes the Stoics recognized only an active and a passive force in the universe, with the active, rational one, permeating and determining the passive one; teleology was confined to one of the Aristotelian causes (the “final” one), while for the Stoics everything is part of a universal causal network; for the Stoics, but not for Aristotle, chance and luck do not really exist, their appearance being due to human ignorance.
Weird as it sounds today, the Stoics thought of both divination and astrology as sciences, and specifically the sciences of figuring out what the Logos (i.e., god, or nature) was up to. (This reminds me of the very funny novels by Douglas Adams about Dirk Gently, “holistic” private detective. Here is the link to the unfortunately too short BBC series.)
Frede comments that when the Stoics said that they wished to “live according to nature” they didn’t mean they believed in some kind of “everything is fine and good” sort of principle, but rather that one needs to learn the nature of the universe and of humanity in order to deal with what happens in nature in the appropriate fashion. She also points out that, by modern standards, the Stoics were pantheists, since they believed that a single substance, the pneuma, permeates the entire world. However, since the pneuma is not present everywhere in the same form, Stoic pantheism is not to be confused with the currently fashionable (in certain philosophical circles) panpsychism.
The Stoics had a complex view of causality. As Frede puts it, at the cosmic level there is only one cause: the active divine spirit known as pneuma. But at the intra-cosmic level there are different (local) causes embedded within portions of the universal causal network. Some of these local causes include human reason, which determines how we interact with our environment.
Frede credits the Stoics for the invention of the nowadays common clear separation between cause and effect. As a consequence of their view on causality, the Stoics thought that fate is to be understood as a network of interacting causes, rather than as a linear chain. Here is a first hint at how the Stoics dealt with the compatibility between external causes and internal human reason: say you see a beautiful woman (or man) in the street. You cannot avoid the “impression” of beauty and whatever emotion it stirs in you. But your reaction (are you going to approach her? Will you keep going your merry way?) is “up to you,” meaning that it is determined by your internal mental makeup.
The author is very clear in section 4 of her chapter that the Stoics thought that human actions are part of the universal causal network, so that given the same external and internal conditions we would react the same way. So in what sense, then, are our actions up to us? Here we need to introduce the (in)famous analogy with a cylinder, described by Cicero. The idea is that the cylinder cannot start moving without an external cause, but once this happens the way the cylinder moves is peculiar to it, because of its structure, which is different from that of other objects.
The cylinder example has caused much confusion, apparently already in the time of the ancient Stoics, largely because it seems to be a bad analogy with a human being: a cylinder is an inert object, not a sentient, thinking, being. It is easy to read the example as reducing humans to objects, thus undermining the Stoic attempt at compatibilism between free will and physical determinism — indeed, this is precisely the way it was read by many of the Stoics’ critics.
Frede, however, attempts a subtle and charitable reading of the cylinder example, where what matters is not that the cylinder cannot possibly do anything but move when pushed by an external force (moving isn’t “up to” the cylinder); rather, the point is, as I said above, that the specific fashion in which the cylinder moves is due to its inner nature. As Frede puts it: “in the case of humans, their inner nature does not consist in their ‘pushability’ but in their particular state of mind and character.” Looking at it this way, it is no surprise that people will act in the same way if exposed to the same inner and outer circumstances: in Stoic parlance, we will always consent to the same impressions.
Whence, then, (moral) responsibility? Again Frede: “responsibility does not depend on the condition that we are always capable of acting otherwise; responsibility depends on the condition that human beings have it ‘in them’ to make up their own minds on how to act.” (For a modern rendition of this, see Frankfurt-style cases in the philosophy of free will.) Crucially, for a practical philosophy like Stoicism, the fact that our personality is preconditioned does not preclude self improvement, because experience of course affects our inner condition. In turn, this explains the Stoics’ concern with the development of the individual, from the cradle through the age of reason: once one is an adult it becomes very difficult to change one’s character.
Interestingly, Frede points out that the Greeks didn’t use the term “free will,” because freedom in this context can neither mean free from external influences (the impressions have to come from somewhere) nor from internal conditioning (there is no such thing as a person without a character). The preferred Stoic phrase, “what is up to us,” then, is particularly apt, especially once the intended meaning is made explicit.
The last section of the chapter comments on the idea of fate. Here Frede is very explicit that the Stoics did not believe in an omniscient being with a predetermined plan. The divine is everywhere, in everything, so the Logos manifests itself as the universal causal network. This is a view that I think is very compatible with modern science and philosophy.
Frede concludes with an interesting observation about why the Stoic approach is not vulnerable to what is known as the argos logos, or “lazy argument.” Here is one version of the argument (which Cicero considered an example of sophism): if it is fated that you will recover (or not) from an illness, then it is pointless for you to seek the help of a doctor. But this won’t do for the Stoics, because local (including human) actions are just as much part of the universal causal nexus as anyone else. Which means that our actions (say, seeking the doctor and following his counsel) are themselves a necessary component of that nexus, instrumental in bringing about the “fated” outcome (we will, or we will not, survive the illness).
As Frede puts it: “the need to treat human beings as autonomous beings is due to human ignorance of the world order at large. It is precisely because we do not know [and we cannot know] what is at stake in the future that we have to do the best we can … The Stoics neither assumed that human beings are capable of such knowledge nor that there is a transcendent divine mind that takes care of everything. The world’s wisdom is immanent in the world itself. … Stoic determinism, therefore, does not lead to resignation, but to a careful study of our capabilities and limitations.”