References

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Flanagan, Owen. 2007. The Really Hard Problem: Meaning in a Material World. Cambridge : MIT Press.

Nietzsche, Friedrich. [1887] 1954. “The Gay Science.  The Portable Nietzsche, ed. WalterKaufmann, chap. 125. New York : Viking.

Sober, Elliott, and DavidSloan Wilson. 1998. Unto Others: The Evolution and Psychology of Unselfish Behavior. Cambridge : Harvard Univ. Press.

Wilson, David Sloan. 2002. Darwin's Cathedral: Evolution, Religion, and the Nature of Society. Chicago : Univ. of Chicago Press.