Originally published in 1928, this book contains substance of the Gifford Lectures which were delivered by Sir Arthur Eddington at the University of Edinburgh in 1927. The text discusses the philosophical outcome of fundamental changes in scientific thought related to areas such as the theory of relativity, quantum theory and thermodynamics.

This book contains lectures given by Sir Arthur Eddington in 1927 on such subjects as the theory of relativity, quantum theory and thermodynamics.