Haldane advanced genetics, population biology and evolutionary theory. This volume emphasizes important developments in natural sciences in the early-20th century. It describes Haldane's views on society, art, religion and economy as seen through the eyes of a politically alert major scientist.

On Scales; Some Dates; On Being the Right Size; Darwinism To-Day; Enzymes; Vitamins; Man as a Sea Beast; Food Control in Insect Societies; Oxygen Want; Water Poisoning and Salt Poisoning; Immunity; Blood Transfusion; Cancer Research; The Fight With Tuberculosis; Food Poisoning; The Time Factor in Medicine; On Being One's Own Rabbit; What Use is Astronomy?; Kant and Scientific Thought; Thomas Henry Huxley; William Bateson; The Future of Biology; Nationality and Research; Scientific Research for Amateurs; Should Scientific Research be Rewarded?; Science and Politics; Eugenics and Social Reform; Occupational Mortality; When I am Dead 1; The Duty of Doubt; Science and Theology as Art Forms; Meroz; Some Enemies of Science; Possible Worlds; The Last Judgment; Epilogue