Four puzzles about life

To surmount the notorious difficulties of defining life, we should evaluate theories of life not by whether they provide necessary and sufficient cond itions for our current preconceptions about life but by how well they expla in living phenomena and how satisfactorily they resolve puzzles about life. On these grounds, the theory of life as supple adaptation gets support fro m the natural and compelling way it resolves the following four puzzles: (a ) How are different forms of life at different levels of the vital hierarch y related? (b) Is there a continuum between life and nonlife? (c) Does life essentially concern a living entity's material composition or its form? (d ) Are life and mind intrinsically connected?