Aristotle, Politics

These considerations therefore make it clear which is the best constitution, and why it is the best; and now that the best has been defined, it is not difficult to see, among the other forms of constitution （inasmuch as we pronounce that there are various forms of democracy and various oligarchies）, what kind is to be placed first, what second, and what next in this order, by reason of one being better and another worse. For at each stage the form nearest to the best one must necessarily be superior, and the form that is more remote from the middle must be inferior—unless one is judging relatively to given conditions: I make this reservation because it is quite possible that although one form of constitution is preferable it may often be more advantageous for certain people to have another form.

The next thing after what has been said is to discuss which constitution is advantageous for which people, and what sort of constitution for what sort of people. Now we must first grasp a general principle that applies equally to all sorts of constitution: it is essential that the part of the state that wishes the constitution to remain should be stronger than the part that does not wish it. But every state consists of both quality and quantity: by quality I mean freedom, wealth, education, good birth, and by quantity the superior numbers of the multitude. And it is possible that, [20] while the quality of the state belongs to one among the parts of which the state consists and its quantity to another part—for example the low-born may be more numerous than the noble or the poor than the rich, yet the more numerous class may not exceed in quantity as much as they fall behind in quality. Hence these two factors have to be judged in comparison with one another.

Where therefore the multitude of the poor exceeds in the proportion stated,¹ here it is natural for there to be democracy, and each kind of democracy in accordance with the superior number of the common people of each sort, for example if the number of the farming class exceeds, the first sort of democracy, but if that of the common laborers and wage-earners, the last sort, and similarly also with the other sorts that lie between these two; but where the class of the well-to-do and notable exceeds in quality more than it falls behind in quantity, here it is natural for there to be an oligarchy, and likewise the various kinds of oligarchy according to the degree of superiority² of the oligarchical multitude.³ But the lawgiver in his constitution must always take in the middle class; if he is making the laws of an oligarchical character he must keep the middle class in view, and if democratic, he must legislate so as to bring them in. And where the number of the middle class exceeds both the extreme classes together, or even one of them only, here it is possible for a constitutional government to be lasting;