Four Puzzles about Life

This paper proposes that theories of life should be evaluated not by whether they provide necessary and sufficient conditions for our current preconceptions about life but by how well they explain living phenomena and how satisfactorily they resolve salient puzzles about life. By these criteria, significant support for the theory of life as supple adaptation (Bedau 1996a) comes from its natural and compelling resolutions to the following four puzzles about life: (1) How are the different forms of life at the different levels of biological hierarchy related? (2) Is there a continuum between life and non-life? (3) Does the essence of life concern the material out of which living entities are composed or the form in which that material exists? (4) Are life and mind intrinsically related? 1. Where to find the nature of life Life presents a problem. We usually have no difficulty distinguishing living from non-living things. A flower, a mushroom, a worm, a bird are alive, and a rock, a mount..