In 1939, there appeared in the series "Actualites Scientifiques et industrilles" three slim volumes of "Etudes galileennes" by Alexandre Koyre who was then distinguished mainly as a historian of philosophy. In these, Professor Koyre examined Galileo's role in the Scientific Revolution with the eyes of a philosopher. He was not the first to do this, but "Etudes" argued for the dominating role of ideas over experience in Galileo's specific thought with a penetration and a singlemindedness that were to have the most profound influence on the next generation of historians of science.