These two volumes form a full portrait of Hans Reichenbach, from the school boy and university student to the maturing and creative scholar, who was as well an immensely devoted teacher and a gifted popular writer and speaker on science and philosophy. We selected the articles for several reasons. Many of them have not pre viously been available in English; many are out of print, either in English or in German; some, especially the early ones, have been little known, and deal with subject-matters other than philosophy of science. The genesis and evolu tion of Reichenbach's ideas appeared to...