Aristotle

It is … constitutional to take … from oligarchy that offices are to be elected, and from democracy that this is not to be on a property-qualification. This then is the mode of the mixture; and the mark of a good mixture of democracy and oligarchy is when it is possible to speak of the same constitution as a democracy and as an oligarchy.

The medieval English poet Chaucer describes his student as being happy by having

The secondary literature on Aristotle is vast. The following is only a small selection.