Upon returning once again to Aristotle’s Nicomachean Ethics, I was able to make some connections between Aristotle’s conception of eudemonia and Zen Buddhism. Being introduced to the Zen tradition recently, I am beginning to notice subtle connections between the eastern precepts and western styles of thinking. This is one of the joys of philosophy, mainly, to consider different belief systems and finding similarities between them. Of course, I am by no means a Zen master. For the sake of philosophy, however, I will explain my observations.
In Book I of Nichomachean Ethics, Aristotle sets out to examine different forms of living. He concludes, near the beginning of the book, that there are three prominent types of life: that of pleasure, political life, or the contemplative life. After Aristotle blueprints the three ways of living, he attempts to clarify a common misconception about external sources of success. The example he provides is one that addresses honor:
… A consideration of the prominent types of life shows that people of superior refinement and of active disposition identify happiness with honor… But it seems too superficial to be what we are looking for, since it is thought to depend on those who bestow honor rather than on him who receives it, but the good we divine to be something of one’s own and not easily taken from one (Cahn and Vitrano 20).
Aristotle asserts that such external dispositions are unsatisfactory. The apparent vanity lies in the fact that honor is a title bestowed by others. This is the weakness of similar external designations; the subject has no control over such titles. It would seem that Aristotle would favor a source of happiness that proceeds from the individual. In this way, the subject has complete control of himself or herself. Happiness, in this view, would solely depend of the individual.
Moreover, Zen principles imply this as well. Freedom does not depend on external things:
The term that Zen uses to express the idea of “freedom” is “jiyū” and it consists of two characters; “ji” meaning “self on its own,” while “yū” means “out of.” When they are used together as a compound, the phrase as a whole designates an action arising out of self on its own.
Nothing outside of the practitioner’s consciousness maintains control over the ego. The mind itself creates its own happiness as well as its own predicaments. In the end, it is up to the subject to interpret reality in complete freedom.
 Nagatomo, Shigenori, "Japanese Zen Buddhist Philosophy", The Stanford Encyclopedia of Philosophy (Winter 2010 Edition), Edward N. Zalta (ed.), URL = <http://plato.stanford.edu/archives/win2010/entries/japanese-zen/>.