Chapter 2: These acts must be such as reason prescribes; they can’t be defined exactly, but must be neither too much nor too little.

But our present inquiry has not, like the rest, a merely speculative aim; we are not inquiring merely in order to know what excellence or virtue is, but in order to become good; for otherwise it would profit us nothing. We must ask therefore about these acts, and see of what kind they are to be; for, as we said, it is they that determine our habits or character.

First of all, then, that they must be in accordance with right reason is a common characteristic of them, which we shall here take for granted, reserving for future discussion the question what this right reason is, and how it is related to the other excellences.

But let it be understood, before we go on, that all reasoning on matters of practice must be in outline merely, and not scientifically exact: for, as we said at starting, the kind of reasoning to be demanded varies with the subject in hand; and in practical matters and questions of expediency there are no invariable laws, any more than in questions of health.

And if our general conclusions are thus inexact, still more inexact is all reasoning about particular cases; for these fall under no system of scientifically established rules or traditional maxims, but the agent must always consider for himself what the special occasion requires, just as in medicine or navigation.

But though this is the case we must try to render what help we can.

First of all, then, we must observe that, in matters of this sort, to fall short and to exceed are alike fatal. This is plain (to illustrate what we cannot see by what we can see) in the case of strength and health. Too much and too little exercise alike destroy strength, and to take too much meat and drink, or to take too little, is equally ruinous to health, but the fitting amount produces and increases and preserves them. Just so, then, is it with temperance also, and courage, and the other virtues. The man who shuns and fears everything and never makes a stand, becomes a coward; while the man who fears nothing at all, but will face anything, becomes foolhardy. So, too, the man who takes his fill of any kind of pleasure, and abstains from none, is a profligate, but the man who shuns all (like him whom we call a “boor”) is devoid of sensibility. Thus temperance and courage are destroyed both by excess and defect, but preserved by moderation.

But habits or types of character are not only produced and preserved and destroyed by the same occasions and the same means, but they will also manifest themselves in the same circumstances. This is the case with palpable things like strength. Strength is produced by taking plenty of nourishment and doing plenty of hard work, and the strong man, in turn, has the greatest capacity for these. And the case is the same with the virtues: by abstaining from pleasure we become temperate, and when we have become temperate we are best able to abstain. And so with courage: by habituating ourselves to despise danger, and to face it, we become courageous; and when we have become courageous, we are best able to face danger.