That pleasure is the Good was held by Eudoxus, on the following grounds. He saw that all
creatures, rational and irrational alike, seek to obtain it; but in every case
（he argued） that which is desirable is good, and that which is most
desirable is the best; therefore the fact that all creatures ‘move in the
thing indicates that this thing is the Supreme Good for all （since everything
finds its own particular good, just as it finds its own proper food）; but that
which is good for all, and which all seek to obtain, is the Good.
His arguments owed their acceptance however more to the excellence of his character than
to their own merit. He had the reputation of being a man of exceptional temperance, and
hence he was not suspected of upholding this view because he was a lover of pleasure, but
people thought it must really be true.
He also held that the goodness of pleasure was equally manifest from the converse: pain
is intrinsically an object of avoidance to all,
therefore its opposite must be intrinsically an object of desire to all.
Again, he argued that that thing is most desirable which we choose not as a means to or
for the sake of something else; but such admittedly is pleasure: we never ask a man for
what purpose he indulges in pleasure—we assume it to be desirable in itself.
He also said that the addition of pleasure to any good—for instance, just or
temperate conduct—makes that good more desirable; but only the good can enhance
Now as for the last argument, it seems only to prove that pleasure is a good, and not
that it is in any way better than any other good; for every good is more desirable when
combined with some other good than in isolation. In fact, a similar argument is employed
to refute the view that pleasure is the Good: the life of pleasure, he urges, is
more desirable in combination with intelligence than without it; but if pleasure combined
with something else is better than pleasure alone, it is not the Good, for the Good is not
rendered more desirable by the addition of anything to it. And it is clear that nothing
else either will be the Good if it becomes more desirable when combined with something
good in itself.
thing is there then of this nature,3
which is attainable by us? for it is something of this nature that
we are in search of.
on the other hand who deny that that which all
creatures seek to obtain is good, are surely talking nonsense. 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.
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.