The population problem : $b A study in human evolution

The population problem by A. M. Carr-Saunders is a scientific treatise written in the early 20th century. It examines population through both quantitative (numbers, growth, resources) and qualitative (heredity, evolution, eugenics) lenses, framing modern concerns within a broad biological and historical perspective. The work aims to connect economic debates with evolutionary theory, surveying how customs, institutions, and biological factors shape fertility and human development. The opening of the work sets out its wartime origins, ambitious scope, and method: to view population questions historically and evolutionarily, and to relate issues of numbers and quality to a common biological basis. It then offers a brisk historical survey from Plato and Roman writers to mercantilists and early economists, culminating in Malthus’s influence, the heated reception of his ideas, early neo-Malthusian advocacy, and the decisive impact on Darwin and Wallace. The text next lays biological groundwork: explaining sexual reproduction, gametes, and fertilization; showing that among animals most ripe ova are fertilized due to vast sperm production and strong sexual instincts; and sketching reflex, instinct, and elementary intelligence. It concludes, for the opening portion, that animal reproduction is essentially “mechanical” (fecundity ≈ realized fertility), whereas in humans conceptual thought and socially shaped practices (e.g., abstinence, abortion, infanticide, sexual customs) intervene, creating a gap between innate fecundity and actual fertility.