The Stoic Epictetus famously believed that his mind was free even if his body was enslaved, and this was enough freedom for him.
The Stoic word for freedom, ἐλευθερία, emphasizes the freedom from external coercion that modern compatibilists argue is the only freedom in the idea of voluntary actions and “free will.”
But long before the Stoics, Aristotle had used “depends on us” (ἐφ’ ἡμῖν), to describe the kind of internal freedom Epictetus prized.
Epictetus knew that some actions in the world were external to his will and out of his control. Like all Stoics, he said we should not be bothered by anything out of our control. Our emotions should only respond to things that we can control, that depend on us, and these he called προαίρεσις.
For Epictetus, good and evil were exclusively involved in things under our control, not in external events. The events themselves were neither good or evil, but these were in our view of events.
Chrysippus had identified things that depend on us as not necessitated (though fated), because they causally depend on our assent (συνκατάθεσις) or dissent. Our assent is needed for us to assume moral responsibility for our actions.
Epictetus taught his students to distinguish clearly those things that were up to us from those beyond our control (ἀπροαίρεσις). These included anything that might, under some circumstances, be beyond our control. Normally we are free to walk about, a prime example of free action for Lucretius, but Epictetus had been put in a cage, so the act of walking was not included for him.
To achieve the Stoic goal of the serene and undisturbed life (ἀταραχία), Epictetus severely limited the things in our power (τά ἐφ’ ἡμῖν) to internal mental activities like assent and intention.
Epictetus very likely accepted Chrysippus’ view that our assent was causally determined (fated), but as long as our assent was in the causal chain we could be said to originate our actions so they “depend on us.” Our actions are not necessitated. If we were to dissent, they would not happen.
But like Chrysippus, his distinguishing things in our control from those not up to us suggests that Epicurus appreciated that our assent and dissent was a choice (προαίρεσις) between alternative possibilities. He said that even god cannot affect decisions that are “up to us.