Originally published in 1961, this book originated in the belief that there was an urgent need for a greater association between philosophers and scientists and of both with men of religion. The problem of bringing this association into being is approached from different angles by the two authors, who, while agreeing on the main thesis, differ on many details, and the discussion is largely concerned with an examination of the points of difference. It ranges over the significance of scientific concepts, such as ether, energy, space and time, the place of mathematics in science and of linguistics in philosophy, the nature of scientific thought in relation to the universe as a whole, problems of life, mind, ethics and theology. It also raises questions of importance concerning the present attitudes of organizations dealing with these matters towards their respective concerns. While the main purpose is always kept in view, a certain amount of discursiveness allows for the introduction of incidental matters of interest in themselves as well as in their relation to the central theme. The book has been written for the layman, and the student, while not, by over-simplification, offending the expert and the erudite.