  Robert Griffiths has recently addressed, within the framework of a
'consistent quantum theory' that he has developed, the issue of whether, as is
often claimed, quantum mechanics entails a need for faster-than-light transfers
of information over long distances. He argues that the putative proofs of this
property that involve hidden variables include in their premises some
essentially classical-physics-type assumptions that are fundamentally
incompatible with the precepts of quantum physics. One cannot logically prove
properties of a system by establishing, instead, properties of a system
modified by adding properties alien to the original system. Hence Griffiths'
rejection of hidden-variable-based proofs is logically warranted. Griffiths
mentions the existence of a certain alternative proof that does not involve
hidden variables, and that uses only macroscopically described observable
properties. He notes that he had examined in his book proofs of this general
kind, and concluded that they provide no evidence for nonlocal influences. But
he did not examine the particular proof that he cites. An examination of that
particular proof by the method specified by his 'consistent quantum theory'
shows that the cited proof is valid within that restrictive version of quantum
theory. An added section responds to Griffiths' reply, which cites general
possibilities of ambiguities that make what is to be proved ill-defined, and
hence render the pertinent 'consistent framework' ill defined. But the vagaries
that he cites do not upset the proof in question, which, both by its physical
formulation and by explicit identification, specify the framework to be used.
Griffiths confirms the validity of the proof insofar as that framework is used.
The section also shows, in response to Griffiths' challenge, why a putative
proof of locality that he has described is flawed.
