 At this point he is claiming incompatibility with relativity only for deterministic hidden-variables theories. Later, however, he spoke of “the apparently essential conflict between any sharp formulation [of quantum theory] and fundamental relativity. That is to say, we have an apparent incompatibility, at the deepest level, between the two fundamental pillars of contemporary theory…” (Bell 1987b and 2004, 172; these are remarks from a meeting held in 1984). Note that this is hedged, and he speaks of “apparently essential” conflict only. In the same year, he wrote, “I am unable to prove, or even formulate clearly, the proposition that a sharp formulation of quantum field theory, such as that set out here, must disrespect serious Lorentz invariance. But it seems to me that this is probably so” (1984, 7; 1987b and 2004, 180).