The controversy between the wave theory and the emission theory of light
early in the nineteenth century has been a subject of numerous studies.
Yet many is- sues remain unclear, in particular, the reasons for
rejecting Young's theory of light. It appears that further progress in
the field requires a better grasp of the overall situation in optics and
related subjects at the time and a more thorough study of every factor
suggested to be of importance for the dispute. This book is intended to
be a step in this direction. It examines the impact of the concept of
interference of light on the development of the early nineteenth-
century optics in general, and the theory of light, in particular. This
is not a his- tory of the wave theory of light, nor is it a history of
the debate on the nature of light in general: it covers only that part
of the controversy which involved the concept of interference. Although
the book deals with a number of scientists, scientific institutions, and
journals, its main character is a scientific concept, the principle of
interference. While discussing the reasons for accepting or rejecting
this concept I have primarily focused on scientific factors, although in
some cases the human factor is examined as well. The book is a revised
Ph. D. dissertation (University of Minnesota, 1984) writ- ten under Alan
E. Shapiro.