This is a reprinting of Flint’s response to EPR, originally signed only as ‘H.T.F.’ Flint begins with a fairly accurate outline of the argument in the EPR paper – with which he agrees – but then he expresses doubts as to the validity of the reality criterion. Without describing the nature of these doubts, he concludes by further agreeing with EPR in desiring a more direct description of reality than the one currently provided by quantum mechanics.

This is a translation of an anonymous report published about Einstein’s seminar in Berlin in November of 1931 dicussed in detail in Chapter 1. The report describes Einstein discussing the meaning of Heisenberg’s uncertainty relations and describing his famous photon-box thought experiment.

This chapter presents a collection of letters between the main protagonists in the EPR debate as analysed in the present volume. Among many other letters, it includes the first ever complete English translation of the correspondence Schrödinger held concerning the EPR paper with, e.g., Einstein, Bohr, Pauli, Born and Teller. He kept these letters in a special folder labelled ‘The Einstein Paradox’, only a small portion of which has previously been discussed in the foundations literature. These historical documents, many of which are published here for the first time, form the basis of our analysis in the beginning chapters of this book.

This chapter introduces in more comprehensive fashion than elsewhere in the literature the interesting role of Heisenberg in the EPR debate. Although we have already published an analysis of Heisenberg’s posthumously published draft response to EPR, only now are we able to situate this excellent primary source in its fullest context, by contributing a chapter describing, for example, Heisenberg’s thinking prior to EPR about interacting systems and hidden variables, the crucial role of Grete Hermann for Heisenberg’s thinking about separability, completeness and observational context, and describing the correspondence between Heisenberg and Bohr discussing Heisenberg’s manuscript.

This is a reprinting of Bohr’s note to Nature advertising his forthcoming response to the EPR paper. It is very brief but contains in essence the argumentative tack Bohr would in fact employ in his full response to EPR.

This is a reprinting of Furry’s response to EPR. Although his response misses the mark, his discussion of an example is intriguing for other aspects of the foundations of quantum mechanics.

This chapter provides a complete list and brief analyses of published and unpublished responses to EPR in 1935 (virtually all of which are reprinted as later chapters in this book). We invite a renewed consideration of certain contributors not much discussed elsewhere in the literature. These include going beyond Kemble’s short criticism of EPR to his ensuing disagreement with Margenau about the viability of an ensemble interpretation of the wavefunction, and also a response to Kemble’s note on EPR by Podolsky himself. We also examine the correspondence between Margenau and Einstein in the wake of EPR, discussing the role of the collapse postulate, and finally we discuss two papers by Furry, which although not entirely satisfactory qua a response to EPR’s arguments, are nevertheless of great potential interest for the foundations literature more generally.

This is a translation of the excerpts published in Naturwissenschaften of Grete Hermann’s 1935 essay on philosophy of quantum mechanics, recently translated into English. Her main thesis, in line with her natural-philosophical training and neo-Kantian commitments, is to argue that quantum mechanics does not refute the principle of causality. Quantum mechanics cannot be completed by, hidden variables, because it is already causally complete (albeit retroductively). In establishing this provocative thesis, she makes important use of Bohr’s principles of correspondence and complementarity and of Weizsäcker's version of the gamma-ray microscope, arguing that the lesson of quantum mechanics is the impossibility of an absolute description of nature independent of the context of observation.

This is a revision of John Trimmer’s English translation of Schrödinger’s famous ‘cat paper’, originally published in three parts in Naturwissenschaften in 1935.

This is a reprinting of Wolfe’s response to the EPR paper. Wolfe insists upon an epistemic reading of the wavefunction, arguing that, under such an interpretation, the EPR paradox dissolves.

This is a reprinting of the famous May 1935 paper in Physical Review by Einstein, Podolsky and Rosen. In this paper, the authors argued that the wavefunction fails to provide a complete description of reality unleashing the debate analysed in this volume.

This chapter details not only the prehistory of EPR but also examines the structure and logic of the EPR paper – including Einstein’s own preferred version of the argument for incompleteness. We here attempt a seamless interweaving of the excellent extant literature with additional details that have emerged from our work and the recent work of others. Some examples of new aspects in this prehistory of EPR include evidence of a ‘proto’ photon-box thought experiment Einstein had developed in connection with his ill-starred collaboration with Emil Rupp in 1926. We also describe the potential importance to this prehistory of Einstein’s paper with Tolman and Podolsky and of Einstein’s seminar and discussions with Schrödinger in Berlin in the early 1930s.

This is a reprinting of Edwin Kemble’s 1935 reply to the EPR paper. Kemble misses EPR’s point by taking their completeness criterion to be merely an epistemic concept; Kemble himself admits as much in a letter to Einstein later that year. His original response to EPR is nevertheless of interest, as Kemble there provides an argument for a statistical interpretation of the wavefunction – a view he attributes to Slater already in a 1929 paper, but for which Kemble provides greater clarity and motivation.

This is a translation of notes by Schrödinger wherein he draws the implications of Einstein’s photon-box thought experiment.