Relative to us rather than an average
Book II distinguishes an arithmetical midpoint from what is proportionate for a person. Six lies midway between ten and two, but a beginner and a trained athlete do not necessarily require the same amount.
Conduct similarly depends on when, toward whom, for what reason and in what manner an emotion or action occurs. The mean concerns an appropriate combination of circumstances, not a uniform quantity.
References: [1]
Courage, temperance and choice
Courage stands between cowardice and rashness; temperance concerns a fitting response to pleasures. Courage does not simply eliminate fear, but involves choosing appropriately in the face of danger.
A single accidentally correct act does not establish virtue. The agent must understand, choose the act for itself and act from a settled character, developed through repeated practice.
References: [1]
Not everything has a correct midpoint
Aristotle explicitly denies that every action has a praiseworthy mean, giving theft among actions whose description already implies wrongdoing. A moderate quantity is therefore not sufficient to make any action right.
This entry concerns Aristotle’s ethical concept. Similar translated terminology does not identify its argument or historical origin with those of Confucian or Buddhist teachings.
References: [1]