N G van Kampen is a well-known theoretical physicist who has had a long and distinguished career. His research covers scattering theory, plasma physics, statistical mechanics, and various mathematical aspects of physics. In addition to his scientific work, he has written a number of papers about more general aspects of science. An indefatigable fighter for intellectual honesty and clarity, he has pointed out repeatedly that the fundamental ideas of physics have been needlessly obscured.As those papers appeared in various journals, partly in Dutch, it was felt that it would be worthwhile to collect them (translating the Dutch material into English) and make them available to a larger audience. This is a book of major importance to scientists and university teachers.