 The question , " What is Life ? " lay behind everything I learned . ... It became clear that the mechanistic concept of life , which dominated our study of medicine at the time , was unsatisfactory ... There was no denying the principle of creative power governing life ; only it was not satisfactory as long as it was not tangible , as long as it could not be described or practically handled . For , rightly , this was considered the supreme goal of natural science . 
