(The argument respecting a man’s proper business (ἔργον) and virtue (ἀρετὴ) seems to be borrowed from Plato — Republic, i. c. 23, p. 352; c. 24, p. 353. Compare also Xenophon — Memorabilia, iv. 2, 14.)
This explanation is delivered by Aristotle as a mere outline, which he seems to think that any one may easily fill up (i. 7). And he warns us not to require a greater degree of precision than the subject admits of: since we ought to be content with a rough approximation to the truth, and with conclusions which are not universally true, but only true in the majority of instances, such being the nature of the premisses with which we deal (i. 3).
Having determined in this manner what Happiness or the Supreme Good consists in, Aristotle next shows that the explanation which he gives of it conforms in a great degree to the opinions previously delivered by eminent philosophers, and fulfils at least all the requisite conditions which have ever been supposed to belong to Happiness (i. 8). All philosophers have from very early times agreed in distributing good things into three classes — Mental, Corporeal, and External. Now the first of these classes is incomparably the highest and most essentially good of the three: and the explanation which Aristotle gives of happiness ranks it in the first class.
Again, various definitions of happiness have been delivered by eminent authorities more or less ancient (πολλοὶ καὶ παλαιοί). Eudoxus laid down the principle that happiness consists in pleasure: others have maintained the opinion that it is entirely independent both of pleasure and pain — that the former is no good, and the latter no evil (i. 12, vii. 11-13, x. 1. 2). Some have placed happiness in virtue: others in prudence: others in a certain sort of wisdom (σοφία τις): others have added to the definition this condition, that pleasure or external prosperity should be coupled with the above-mentioned objects (i. 8). The moral doctrines propounded by Zeno and Epicurus were therefore in no way new: how far the reasonings by which these philosophers sustained them were new we cannot judge accurately, from the loss of the treatises of Eudoxus and others to which Aristotle makes reference.
Now, in so far as virtue is introduced, the explanation of Happiness given by Aristotle coincides with these philosophers and improves upon them by substituting the active exercise of virtuous habits in place of the mere possession of virtue. And in regard to pleasure, the man who has once acquired habits of virtuous agency stands in no need of pleasure from without, as a foreign accessory: for he finds pleasure in his own behaviour, and he would not be denominated virtuous unless he did so: “Now (he says) their life stands in no need of pleasure, like an extraneous appendage, but has pleasure in itself� (ii. 8). Again, ii. 3, he says that “the symptom of a perfect habit is the pleasure or pain which ensues upon the performance of the acts in which the habit consists: for the man who abstains from bodily pleasures and rejoices in doing so, is temperate, while he who does it reluctantly and painfully, is intemperate. And the man who sustains dangers with pleasure, or at least without pain, is courageous: if with pain, he is a coward. For ethical virtue has reference to our pleasures and pains: it is on account of pleasure that we commit vicious acts, and on account of pain that we shrink from virtuous performances. Wherefore, as Plato directs, we ought to be trained at once from our infancy by some means or other so as to feel pleasure and pain from the proper sources: for that is the right education.�
Moreover, the man who is in the active exercise of virtue derives his pleasure from the performance of that which is the appropriate business of humanity, so that all his pleasures are conformable to the pleasures natural to man and therefore consistent with each other: whereas the pleasures of most people are contradictory and inconsistent with each other, because they are not conformable to our nature (i. 8).
It is not easy to understand perfectly what Aristotle means by saying that the things agreeable to the majority of mankind are not things agreeable by nature. The construction above put upon this expression seems the only plausible one — that those pleasures which inhere in the performance of the appropriate business of man, are to be considered as our natural pleasures; those which do not so inhere, as not natural pleasures: inasmuch as they arise out of circumstances foreign to the performance of our appropriate business.
This however hardly consists with the explanation which Aristotle gives of τὸ φύσει — in another place and with reference to another subject. In the Magna Moralia (i. 34, pp. 1194-1195 Bek.), in distinguishing between natural justice (τὸ δίκαιον φύσει) and conventional justice (τὸ δίκαιον νόμῳ), he tells us that the naturally just is that which most commonly remains just. (Similarly Ethic. Eudem. iv. 14, p. 1217 Bek.) That which exists by nature (he says) may be changed by art and practice; the left hand may by these means be rendered as strong as the right in particular cases, but if in the greater number of cases and for the longer portion of time the left remains left and the right remains right, this is to be considered as existing by nature.
If we are to consider that arrangement as natural which we find to prevail in the greatest number of cases and for the greatest length of time, then undoubtedly the pleasures arising out of virtuous active behaviour must be regarded as less natural than those other pleasures which Aristotle admits to form the enjoyment of the majority of mankind.
But again there is a third passage, respecting nature and natural arrangements, which appears scarcely reconcilable with either of the two opinions just noticed. In Eth. Nicom. ii. 1: “Ethical virtue is a result of habit, whence it is evident that not one of the ethical virtues exists in us by nature. For none of those things which exist by nature is altered by habit. For example, the stone which naturally moves downwards cannot be habituated to move upwards, not even if a man should endeavour so to habituate it by throwing it upwards ten thousand times; nor in like manner fire downwards: nor can any other of the things formed by nature in one way be changed by habit to any other than that natural way. Virtues therefore are not generated in us either by nature, or contrary to nature; but we are formed by nature so as to be capable of receiving them, and we are perfected in them through the influence of habit.�