This book, outstanding in its field, presents in a clear, impressively thorough way the philosophical problems concerned with relativity theory and the topology and metrics of space and time. Many of the author's points will be familiar to the readers of his earlier articles, some of which this work is meant to supersede. Unifying all the many discussions is a rigorous and thorough-going empiricism that relies heavily on the results of investigations of physicists and mathematicians and that masterfully clips the (...) wings of those who would take flight from these results into the airy realms of speculative cosmology.—A. E. F. (shrink)