This is a new publication of the Collected Papers On Wave Mechanics by Erwin Schrödinger - one of the founding fathers of quantum physics.This valuable book should prove attractive to experts, students and all interested in the origin, the foundations and the philosophy of quantum physics. A particular reason for this is that Schrödinger discusses two issues which are still (in the 21st century) unsettled - the physical meaning of the wave function and the statistical nature of quantum physics. Like Einstein, Schrödinger was not satisfied with the statistical description of quantum phenomena: "The question whether the solution of the difficulty is really to be found only in the purely statistical interpretation of the field theory which has been proposed in several quarters must for the present be left unsettled. Personally I no longer regard this interpretation as a finally satisfactory one, even if it proves useful in practice. To me it seems to mean a renunciation, much too fundamental in principle, of all attempt to understand the individual process."