This volume is divided into five parts. The title of the volume refers primarily to part I, which is by far the largest and comprises papers discussing the fundamental questions of biology and related psychological and philosophical problems. Following the reproduction of papers brought to publication by Bohr, there is a separate Appendix to Part I including some of Bohr's most interesting and substantive unpublished contributions in this area. The papers in Part I span the last thirty years of Bohr's life and display his great interest in biological problems and his unremitting efforts to...