We cannot respond to impressions or any external event in a manner inconsistent with our current moral character. This fact comes from the stoic conception of determinism. Nature and humans alike behave in a predictable manner based upon their nature. We really wouldn't want it to be any other way. Predictability is an essential part of our survival.
Keep in mind that what injures you is not people who are rude or aggressive but your opinion that they are injuring you. So whenever someone provokes you, be aware that the provocation really comes from your own judgment. Start, then, by trying not to get carried away by the impression. Once you pause and give yourself time, you will more easily control yourself. (Ench 20)
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