There's no doubt that anger starts when we think someone has wronged us. But here's the question: Does anger immediately follow that thought and spring up without any help from our minds? Or does anger need our mind's cooperation to get started? We Stoics believe that anger cannot do anything by itself without our mind's approval. Think about what happens: we form the idea that we've been wronged, we want revenge, and we connect two thoughts — that we shouldn't have been hurt and that we should strike back. A simple impulse that happens without our permission cannot do all this. That impulse would be simple. But this is complex, made up of several parts. The person understands that something happened. He gets indignant about it. He condemns what was done. And he seeks revenge. All these things cannot happen without his mind agreeing to the thoughts that affected him.
There is no doubt that anger is roused by the appearance of an injury being done: but the question before us is, whether anger straightway follows the appearance, and springs up without assistance from the mind, or whether it is roused with the sympathy of the mind. Our (the Stoics') opinion is, that anger can venture upon nothing by itself, without the approval of mind: for to conceive the idea of a wrong having been done, to long to avenge it, and to join the two propositions, that we ought not to have been injured and that it is our duty to avenge our injuries, cannot belong to a mere impulse which is excited without our consent. That impulse is a simple act; this is a complex one, and composed of several parts. The man understands something to have happened: he becomes indignant thereat: he condemns the deed; and he avenges it. All these things cannot be done without his mind agreeing to those matters which touched him.