Einstein insisted that the only acceptable interpretation of the quantum theory was an ensemble interpretation, that this way of understanding the quantum formalism eliminated all the problems associated with interpreting the theory as a complete description of individual systems. But he never developed his ensemble interpretation in any detail or explained how it was supposed to resolve the difficulties with the individual interpretation. We offer a reconstruction of Einstein's position that is consonant with his other beliefs and examine the “prism” (...) reconstruction recently proposed by Arthur Fine. We show the plausibility of our reading, as an interpretation of Einstein, and criticize Fine's proposal, as an alternative interpretation and as an attempt to understand quantum theory. As we reconstruct it, Einstein's position is, nevertheless, problematic. We therefore conclude with a plausible, if unoriginal, suggestion as to the reason he failed to develop his remarks on ensembles more fully. (shrink)

This article discusses the historical similarities and differences between Schroedinger's and de Broglie's ideas on wave mechanics and gives a biographical account of their scientific relationship. Their arguments over questions such as quantum jumps, the viability of particles within wave mechanics theory, and the inclusion of space, time, and relativity in quantum mechanics are analyzed. The final section of the paper considers the overall role of Schroedinger's ideas in modern quantum mechanics.