Aristotle, Eudemian Ethics

[1218b] [1] (for universality might be an attribute of even a small good), and also it is not practicable; for medical science does not study how to procure an attribute that belongs to anything, but how to procure health, and similarly also each of the other practical sciences. But 'good' has many meanings, and there is a part of it that is beautiful, and one form of it is practicable but another is not. The sort of good that is practicable is that which is an object aimed at, but the good in things unchangeable is not practicable. It is manifest, therefore, that the Absolute Good we are looking for is not the Form of good, nor yet the good as universal, for the Form is unchangeable and impracticable, and the universal good though changeable is not practicable. But the object aimed at as End is the chief good, and is the cause of the subordinate goods and first of all; so that the Absolute Good would be this—the End of the goods practicable for man. And this is the good that comes under the supreme of all the practical sciences, which is Politics and Economics and Wisdom; for these states of character differ from the others in the fact that they are supreme (whether they differ at all from one another must be discussed later on¹). And that the End stands in a causal relation to the means subordinate to it is shown by the method of teachers; they prove that the various means are each good by first defining the End, because the End aimed at is a cause: for example, since to be in health is so-and-so, what contributes to health must necessarily be so-and-so; [20] the wholesome is the efficient cause of health, though only the cause of its existing—it is not the cause of health's being a good. Furthermore nobody proves that health is a good (unless he is a sophist and not a physician—it is sophists that juggle with irrelevant arguments), any more than he proves any other first principle.

After this we must take a fresh starting-point² and consider, in regard to the good as End for man and in regard to the best of practicable goods, how many senses there are of the term 'best of all,' since this is best.