Amizade e emoções de rivalidade em Aristóteles: uma origem comum?

As in Aristotle friendly feelings are often coupled with attitudes of rivalry, one may askwhether there is in the soul, according to Aristotle, a common origin for theseapparently opposed emotions. A positive answer to this question will provide one with abetter understanding of the Aristotelian notion of friendship, and, at the same time, witha deeper insight of the role thumos has in the Aristotelian moral psychology.