First published in 1936, this volume contains six of the Halley Stewart Lectures - originally founded "For Research towards the Christian Ideal in All Social Life" - by some of the greatest of English scientists of the mid-20th century, each a leading authority in his respective field: cosmology, physics, meteorology, medicine and genetics. The final lecture considers the relationship between scientific knowledge and human ideals, commenting on the paradox that a century which produced such scientific advance also witnessed the most concentrated period of social, economic and political turmoil in world history.