AbstractA consistent application of probabilistic theory is able to resolve traditionally perplexing quantum‐theoretical issues, such as those concerned with quantum measurement procedures, wave‐corpuscle duality, the reality of particle motion, hidden variables, the proper choice of the energy operator, the energy‐time uncertainty relation, conservation laws, and the notion of wave packets. Germane to this resolution is the consideration that quantum physics deals with abstract physical systems and not with single measurements performed on concrete systems. We examine the two‐slit diffraction phenomenon and those hypothetical experiments which attempt the simultaneous measurement of any coordinate and its conjugate momentum; their customary interpretations are shown to be basically incorrect. A logical error is likewise found to underlie the usual assertion that the ordinary rule for the addition of probabilities breaks down in quantum physics. And the confusion of energy with the Hamiltonian function is identified as the cause for a number of prevailing wrong conclusions. The probabilistic approach furthermore invalidates PAULI'Sproof that time is a socalled c‐number. Our treatment also readily exposes the fallacy in the common assumption that Schrödinger's wave equation goes over into the Hamilton‐Jacobi equation when the classical limit i