Reciprocity: Competition and cooperation are like nature's yin and yang, claim two French biologists. Today, recent biological and psychological research on reciprocity is based on both biochemistry, game theory, empirical examination of symbiotic relationships and the new sociobiology's theories of group selection.
ESSAY: Today, the extreme state is different than in the post-war period, when Sartre and Heidegger wrote about anxiety and authenticity. The existential threat today lies primarily in an uncertain planetary future.