Time in quantum mechanics: a story of confusion

In this article I trace the genesis of the problem in the work of six of the founding fathers of modern quantum theory: Dirac, Heisenberg, Bohr, Schrödinger, von Neumann and Pauli, covering the period 1925-1933. Little coherence between the views of these authors has been found but, from the beginning, the mixing of notions from classical and quantum mechanics on the one hand, and from relativity theory on the other, has been an important source of confusion.