Aristotle, Nicomachean Ethics
H. Rackham, Ed.

For what all think to be good, that, we assert, is good; and he that subverts our belief in the opinion of all mankind, will hardly persuade us to believe his own either. If only the irrational creatures strove to obtain what is pleasant, there would have been some sense in this contention; but inasmuch as beings endowed with intelligence do so too, how can it be right? And perhaps even the lower animals possess an instinct superior to their own natures, which seeks to obtain the good appropriate to their kind.

[5] Again, these thinkers' refutation of the argument from the converse appears equally unsound. They pain say, if pain is bad, it does not follow therefore that pleasure is good: for an evil can also be opposed to an evil and to a thing that is neither good nor evil: a statement which is indeed sound enough, but which does not apply to the things in question. If both pleasure and pain were in the class of evils, both would be also of necessity things to be avoided, and if in the class of things neutral, neither ought to be avoided, or they ought to be avoided alike; but as it is we see men avoid pain as evil and choose pleasure as good; it is therefore as good and evil that they are opposed.

3. Nor yet does it follow that if pleasure is not a quality, therefore it is not a good. Virtuous activities are not qualities either, nor is happiness.

[2] Again they argue¹ that good is definite, but that pleasure is indefinite, because it admits of degrees. Now （a） if they base this judgement on the fact that one can be more or less pleased, the same argument will apply to Justice and the other virtues, the possessors of which are clearly spoken of as being more or less virtuous; for example, A may be more just or brave, and may act more, or less, justly or temperately, than B. If on the other hand （b） they judge by the nature of the pleasures themselves, I am afraid they do not state the right ground for their conclusion, if it be true that there are two kinds of pleasures, unmixed as well as mixed.²

[3] Again, （c） why should not pleasure be like health, which is definite although it admits of degrees? For health is not constituted by the same proportion of elements in all persons; nor yet by one particular proportion in the same person always, but when it is in process of dissolution it still lasts for a certain time, and therefore it varies in degree. It is possible therefore that the same may be the case with pleasure.

[4] Again, they postulate³ that the Good is perfect, whereas a motion or process of generation is imperfect, and then they attempt to prove that pleasure is a motion or process. This appears to be a mistake. （a） It would seem that pleasure is not a motion; for we hold it to be a property of all motion to be quick or slow—if （as with the motion⁴ of the firmament） not absolutely, then relatively to some other moving body. But pleasure possesses neither absolute nor relative velocity. You can become pleased quickly, just as you can get angry quickly: