The Controversy over the Nature of Time-Symmetric Quantum Counterfactuals: A Response to Kastner

Lev Vaidman A

Lev Vaidman A

D. J. Miller

Robert B. Griffiths

Lev Vaidman A

There is a trend to consider counterfactuals as invariably time-asymmetric. Recently, this trend manifested itself in the controversy about validity of counterfactual application of a time-symmetric quantum probability rule. Kastner (2003) analyzed this controversy and concluded that there are time-symmetric quantum counterfactuals which are consistent, but they turn out to be trivial. I correct Kastner's misquotation of my defense of time-symmetric quantum counterfactuals and explain their non-trivial aspects, thus contesting the claim that counterfactuals have to be time-asymmetric.

Ulrich Mohrhoff

Kastner's (Philosophy of Science 70, 2003, pp. 145--163) recent objections to the counterfactual usage of the time-symmetric Aharonov-Bergmann-Lebowitz rule by the author, especially her claims that the resulting time-symmetric quantum counterfactuals are vacuous or invalid, are examined and shown to be unfounded or beside the point.