Others call it altogether vile and worthless [party of Speusippus].

Of these last, some perhaps really think so; but the rest are actuated by the necessity of checking men's too great proneness to it, and disparage it on that account.

This policy Aristotle strongly censures, and contends for the superior efficacy of truth (I.).
The arguments urged by Eudoxus as proving pleasure to be the chief good, are, (1) That all beings seek pleasure; (2) and avoid its opposite, pain; (3) that they seek pleasure as an end-in-itself, and not as a means to any farther end; (4) that pleasure, added to any other good, such as justice or temperance, increases the amount of good; which could not be the case, unless pleasure were itself good.
Yet this last argument (Aristotle urges) proves pleasure to be _a_ good, but not to be _the_ Good; indeed, Plato urged the same argument, to show that pleasure could _not_ be The Good: since The Good (the Chief Good) must be something that does not admit of being enhanced or made more good.

The objection of Speusippus,--that irrational creatures are not to be admitted as witnesses,--Aristotle disallows, seeing that rational and irrational agree on the point; and the thing that seems to all, must be true.

Another objection, That the opposite of pain is not pleasure, but a neutral state--is set aside as contradicted by the fact of human desire and aversion, the two opposite states of feeling (II.).
The arguments of the Platonists, to prove that pleasure is not good, are next examined.