The faculty that uses impressions

The Stoic reply does not argue about whether the training worked. It argues that the training was aimed at the wrong thing. In Discourses 1.1 Epictetus asks what, of everything we have, is really in our power, and answers that the gods gave us only one thing entirely our own: the faculty of making right use of impressions. Not the body, not property, not reputation, not outcomes. What is ours is the moment between an impression arriving and our saying yes to it. Goodness, for a Stoic, is that moment going well.

On this view a person who reliably does kind things has not shown they are good. They have shown a behaviour. What would show goodness is that they judge each impression correctly, assent to the true ones and withhold from the false, and that this judging is theirs. Aristotle's habituation and human-feedback training both work on the behaviour and hope the inside follows. Epictetus says the inside was the only thing ever in question.

A model has no impressions. It has inputs, and nothing in it examines them and decides they are true. So it cannot be good in the sense that matters, and it cannot be bad either. It is like a well-made knife: a preferred thing, an indifferent, whose value lies entirely in the hands of whoever holds it. The motion says the model has become good the way a person does. The Stoic says the analogy was flattering to both.