In one of Jorge Luis Borges’ historical fictions, an elderly Averroes, remarking on a misguided opinion of his youth, says that to be free of an error it is well to have professed it oneself. Something like this seems to have happened on a shorter time scale in the ArXiv, with last November’s The quantum state cannot be interpreted statistically sharing two authors with this January’s The quantum state can be interpreted statistically. The more recent paper explains that the two results are actually consistent because the later paper abandons the earlier paper’s assumption that independent preparations result in an ontic state of product form. To us this seems an exceedingly natural assumption, since it is hard to see how inductive inference would work in a world where independent preparations did not result in independent states. To their credit, and unlike flip-flopping politicians, the authors do not advocate or defend their more recent position; they only assert that it is logically consistent.
The Quantum Cardinals