The recent far-reaching developments of Physics have produced the widespread impression that all those ideas of mechanics and mechanism, which were so influential in the nineteenth century, have now been completely abandoned, because they have proved to be quite inadequate as explanations, or even as mere descriptions, of the ultimate constitution of the physical world. “Has not modern physics”, asks Prof. Millikan, “thrown the purely mechanistic view of the universe root and branch out of its house?“ It is frequently contended, (...) still further, that the place of these concepts has been taken by others, very closely approximating to biological, or even to psychological, interpretations of all natural phenomena; the physics of today, in short, and yet more of tomorrow, is essentially non-mechanical. (shrink)