Abstract
A publication by Professor Margenau is always of interest to persons concerned with philosophy of science. This is especially true, however, of his recently published book, The Nature of Physical Reality; for this book, dealing with basic epistemological problems arising from the development of modern quantum mechanics, is the most comprehensive and most systematic formulation of its author's philosophical position and is at the same time conceived as a “challenge” to “uncritical realism, unadorned operationalism, and radical empiricism”—to points of view, that is, which Professor Margenau regards as “outmoded and in disharmony with the successful phases of contemporary physics”.