Aristotle, Politics

[1328b] [1] for as each set of people pursues participation in happiness in a different manner and by different means they make for themselves different modes of life and different constitutions. And we must also further consider how many there are of these things referred to that are indispensable for the existence of a state; for among them will be the things which we pronounce to be parts of a state, owing to which their presence is essential. We must therefore consider the list of occupations that a state requires : for from these it will appear what the indispensable classes are. First then a state must have a supply of food; secondly, handicrafts （since life needs many tools）; third, arms （since the members of the association must necessarily possess arms both to use among themselves and for purposes of government, in cases of insubordination, and to employ against those who try to molest them from without）; also a certain abundance of money, in order that they may have enough both for their internal needs and for requirements of war; fifth, a primary need, the service of religion, termed a priesthood; and sixth in number and most necessary of all, a provision for deciding questions of interests and of rights between the citizens. These then are the occupations that virtually every state requires （for the state is not any chance multitude of people but one self-sufficient for the needs of life, as we say,¹ and if any of these industries happens to be wanting, it is impossible for that association to be absolutely self-sufficient）. It is necessary therefore for the state to be organized [20] on the lines of these functions; consequently it must possess a number of farmers who will provide the food, and craftsmen, and the military class, and the wealthy, and priests and judges to decide questions of necessity² and of interests.

These matters having been settled, it remains to consider whether everybody is to take part in all of these functions （for it is possible for the whole of the people to be at once farmers and craftsmen and the councillors and judges）, or whether we are to assume different classes corresponding to each of the functions mentioned, or whether some of them must necessarily be specialized and others combined. But it will not be the same in every form of constitution; for, as we said,³ it is possible either for all the people to take part in all the functions or for not all to take part in all but for certain people to have certain functions. In fact these different distributions of functions are the cause of the difference between constitutions: democracies are states in which all the people participate in all the functions, oligarchies where the contrary is the case. But at present we are studying the best constitution, and this is the constitution under which the state would be most happy, and it has been stated before⁴ that happiness cannot be forthcoming without virtue; it is therefore clear from these considerations that in the most nobly constituted state, and the one that possesses men that are absolutely just, not merely just relatively to the principle that is the basis of the constitution, the citizens must not live a mechanic or a mercantile life （for such a life is ignoble and inimical to virtue）, nor yet must those who are to be citizens in the best state be tillers of the soil