Aristotle, Nicomachean Ethics
H. Rackham, Ed.

To criticize a particular subject, therefore, a man must have been trained in that subject: to be a good critic generally, he must have had an all-round education. Hence the young are not fit to be students of Political Science.¹ For they have no experience of life and conduct, and it is these that supply the premises and subject matter of this branch of philosophy. [6] And moreover they are led by their feelings; so that they will study the subject to no purpose or advantage, since the end of this science is not knowledge but action. [7] And it makes no difference whether they are young in years or immature in character: the defect is not a question of time, it is because their life and its various aims are guided by feeling; for to such persons their knowledge is of no use, any more than it is to persons of defective self-restraint.² But Moral Science may be of great value to those who guide their desires and actions by principle. [8]

Let so much suffice by way of introduction as to the student of the subject, the spirit in which our conclusions are to be received, and the object that we set before us.4.

To resume, inasmuch as all studies and undertakings are directed to the attainment of some good, let us discuss what it is that we pronounce to be the aim of Politics, that is, what is the highest of all the goods that action can achieve. [2] As far as the name goes, we may almost say that the great majority of mankind are agreed about this; for both the multitude and persons of refinement speak of it as Happiness,³ and conceive ‘the good life’ or ‘doing well’⁴ to be the same thing as ‘being happy.’ But what constitutes happiness is a matter of dispute; and the popular account of it is not the same as that given by the philosophers. [3] Ordinary people identify it with some obvious and visible good, such as pleasure or wealth or honor—some say one thing and some another, indeed very often the same man says different things at different times: when he falls sick he thinks health is happiness, when he is poor, wealth. At other times, feeling conscious of their own ignorance, men admire those who propound something grand and above their heads; and it has been held by some thinkers⁵ that beside the many good things we have mentioned, there exists another Good, that is good in itself, and stands to all those goods as the cause of their being good. [4]

Now perhaps it would be a somewhat fruitless task to review all the different opinions that are held. It will suffice to examine those that are most widely prevalent, or that seem to have some argument in their favour. [5]

And we must not overlook the distinction between arguments that start from first principles and those that lead to first principles. It was a good practice of Plato to raise this question, and to enquire whether the true procedure is to start from or to lead up to one's first principles,