1. They are mediocrities (μεσότητες).
2. They are habits, generated by particular actions often repeated.
3. When generated, they have a specific influence of their own in facilitating the performance of actions of the same class.
4. They are in our own power originally, and voluntary.
5. They are under the direction of right reason.
It is to be observed that our actions are voluntary from the beginning to the end — the last of a number of repeated actions is no less voluntary than the first. But our habits are voluntary only at the beginning — they cease to be voluntary after a certain time — but the permanent effect left by each separate repetition of the action is inappreciable (iii. 5).
Aristotle then proceeds to an analysis of the separate virtues — Courage, Temperance, Liberality, Magnificence, Magnanimity, Gentleness, Frankness, Simplicity, Elegant playfulness, Justice, Equity, &c. He endeavours to show that each of these is a certain mediocrity — excess lying on one side of it, defect on the other.
There are various passages of Aristotle which appear almost identical with the moral doctrine subsequently maintained by the Stoic school: for example — iii. 6 — “In like manner he ought not to fear penury, nor sickness, nor in any way such things as arise not from moral baseness nor are dependent on himself.�
The courageous man is afraid of things such as it befits a man to fear, but of no others: and even these he will make head against on proper occasions, when reason commands and for the sake of honour, which is the end of virtue (iii. 7). To fear nothing, or too little, is rashness or insanity: to fear too much, is timidity: the courageous man is the mean between the two, who fears what he ought, when he ought, as he ought, and with the right views and purposes (ib.). The μοιχὸς (adulterer) exposes himself often to great dangers for the purpose of gratifying his passion: but Aristotle does not hold this to be courage. Neither does he thus denominate men who affront danger from passion, or from the thirst of revenge, or from a sanguine temperament — there must be deliberate preference and a proper motive, to constitute courage — the motive of honour (iii. 8).
The end of courage (says Aristotle) is in itself pleasant, but it is put out of sight by the circumstances around it: just as the prize for which the pugilist contends is in itself pleasurable, but being of small moment and encompassed with painful accessories, it appears to carry with it no pleasure whatever. Fatigue, and wounds and death are painful to the courageous man — death is indeed more painful to him, inasmuch as his life is of more value: but still he voluntarily and knowingly affronts these pains for the sake of honour.