Book 1: The End.
Chapter 6: Various arguments to show against the Platonists that there cannot be one universal good.
Dismissing these views, then, we have now to consider the “universal good,” and to state the difficulties which it presents; though such an inquiry is not a pleasant task in view of our friendship for the authors of the doctrine of ideas. But we venture to think that this is the right course, and that in the interests of truth we ought to sacrifice even what is nearest to us, especially as we call ourselves philosophers. Both are dear to us, but it is a sacred duty to give the preference to truth.
In the first place, the authors of this theory themselves did not assert a common idea in the case of things of which one is prior to the other; and for this reason they did not hold one common idea of numbers. Now the predicate good is applied to substances and also to qualities and relations. But that which has independent existence, what we call “substance,” is logically prior to that which is relative; for the latter is an offshoot as it were, or [in logical language] an accident of a thing or substance. So [by their own showing] there cannot be one common idea of these goods.
Secondly, the term good is used in as many different ways as the term “is” or “being:” we apply the term to substances or independent existences, as God, reason; to qualities, as the virtues; to quantity, as the moderate or due amount; to relatives, as the useful; to time, as opportunity; to place, as habitation, and so on. It is evident, therefore, that the word good cannot stand for one and the same notion in all these various applications; for if it did, the term could not be applied in all the categories, but in one only.
Thirdly, if the notion were one, since there is but one science of all the things that come under one idea, there would be but one science of all goods; but as it is, there are many sciences even of the goods that come under one category; as, for instance, the science which deals with opportunity in war is strategy, but in disease is medicine; and the science of the due amount in the matter of food is medicine, but in the matter of exercise is the science of gymnastic.
Fourthly, one might ask what they mean by the “absolute:” in “absolute man” and “man” the word “man” has one and the same sense; for in respect of manhood there will be no difference between them; and if so, neither will there be any difference in respect of goodness between “absolute good” and “good.”
Fifthly, they do not make the good any more good by making it eternal; a white thing that lasts a long while is no whiter than what lasts but a day.
There seems to be more plausibility in the doctrine of the Pythagoreans, who [in their table of opposites] place the one on the same side with the good things [instead of reducing all goods to unity]; and even Speusippus* seems to follow them in this.
However, these points may be reserved for another occasion; but objection may be