For example, if a person says something critical to us, that is not bad; or, if something complimentary is said, that is not good, because such things are externals and not in our power to control.
By exerting the power of choice, it is possible to maintain equanimity in the face of either criticism and praise, which is a moral good.
On the other hand, when people become troubled by criticism, or elated by praise, that is a moral evil because they have misjudged impressions by thinking that things not in their power (such as criticism or praise) have value, and by doing that they place a measure of control of their own life in the hands of others.
Try, therefore, in the first place, not to be carried away by the impression; for if you once gain time and respite, you will find it easier to control yourself.
[6] By exerting their prohairesis (will, volition, or choice), people can choose rationally how to react to impressions.