Our future was with the collective, but our survival was with the individual, and the paradox was killing us everyday. John Le Carre Smiley's People (1979) Since the time of Ancient Greek lyrical poetry, it has been one of man's dreams to explain his own conduct. This is the background to all his activities, from literature to speculative philosophy, including those odds and ends which, for want of a better name and more precise boundaries are called "human science". Over the past nine or ten years a new member has been added to this inquisitive family, one which, moreover, claims to be scientific to an extremely high degree: biology. This is in fact a recurrent event, since theses designed to introduce causal biological expla nations into the general field of human action had already been formulated on at least two occasions (in original Darwinism and the Neo-Darwinist synthesis). Ethologists and sociobiologists are today taking over and as suring us that they have the necessary tools to provide an answer to what perhaps seemed the most slippery subject in the hands of science: the social being. As might be expected, philosophers have reacted with some scepticism. Though human conduct is undoubtedly subject to determinants, the lion's share of responsi bility lies with society itself. At the time when biology was beginning to develop the theories necessary to overcome cre ationism, Karl Marx had already managed to construct highly sophisticated interpretive models of human social behaviour.