for in the world both of nature and of art the inferior always exists for the sake of the better or superior, and the better or superior is that which has a rational principle.
 Aristotle, Politics (4th century BC). copy citation

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Author Aristotle
Source Politics
Topic art principles
Date 4th century BC
Language English
Reference
Note Translated by Benjamin Jowett
Weblink http://classics.mit.edu/Aristotle/politics.html

Context

“Now the soul of man is divided into two parts, one of which has a rational principle in itself, and the other, not having a rational principle in itself, is able to obey such a principle. And we call a man in any way good because he has the virtues of these two parts. In which of them the end is more likely to be found is no matter of doubt to those who adopt our division; for in the world both of nature and of art the inferior always exists for the sake of the better or superior, and the better or superior is that which has a rational principle. This principle, too, in our ordinary way of speaking, is divided into two kinds, for there is a practical and a speculative principle. This part, then, must evidently be similarly divided. And there must be a corresponding division of actions;” source