Max von Laue

"Though the churches, in general, abstained from interfering officially, the scientific activities of the physicists have always been influenced by their private religious views. The latter, of course, were not necessarily identical with the ecclesiastical doctrines, but the philosophical attitudes of the scientists were affected, at least to some extent, by the prevailing religious thought. Kepler, Descartes, Leibniz, and Newton freely acknowledged this influence; it played a part in the principle of least action in the eighteenth century. After this period, in which Kant's philosophy proclaimed the complete independence of scientific understanding and religious belief, not much more about it is found in physical writings. However, this by no means signifies that the investigational urge of later scientists was not intimately connected with their religiosity. The tenet that the scientific experience of truth in any sense is "theoria," i.e., a view of God, might be said sincerely about the best of them. The search for knowledge without regard to its applicability for use has been "an essential trait of man through the centuries, a sign of his higher origin.""

"In the beginning was mechanics."

"Quantum physics, which in contrast to the earlier theory, is characterized by the appearance of the elementary action quantum h and the designation of states in material systems by whole numbers, dates as theory only from the beginning of the twentieth century... However, some of its experimental roots extend far back into the nineteenth century. Of course, the measurements of the intensity of heat radiation which brought the change are a product of the last decade of that century. However, the photoelectric effect, and the wavelengths of the line and band spectra and also the dependence of the specific heats of certain substances on temperature had been known decades earlier. The older physics had hoped to arrive at an explanation of these findings; otherwise it is difficult to understand why Philipp von Jolly (1809-1884) told the inquiring young Planck that physics was essentially worked out and the pursuit of this science accordingly could hardly be very profitable. What appeared from time to time concerning line spectra could no longer stand up under rigid criticism when the discussion was based on the older ideas. On the other hand, quantum physics handled these problems more or less easily and in addition elucidated much of the newly acquired experimental observations."