The strong focus of the early Third Republic's philosophers on science is hardly unusual. The identity of philosophy has always been intimately associated with that of science. We can think of philosophy's premodern period as the time, before the scientific revolution, when it was identical with science, when philosophy was simply the enterprise of understanding the world in all its aspects. The scientific revolution destroyed this identity by showing that there was at least one domain – knowledge of the material world – where philosophy's methods of rational insight and logical argument were not adequate. Here, it was gradually discovered (and, of course, anticipations of the discovery can be traced back to the very beginnings of Greek inquiry) that the empirical method of testing conjectures by observing whether their consequences were true was far superior. No doubt philosophy, considered simply as our search for truth, could be regarded as employing this method.