 I do not recall logicians having to seek the blessing of physicists before pursuing this or that line of inquiry, or of the interest, significance or legitimacy (“now entitled to propose...”, no less) of such inquiries being dependent on empirical and theoretical findings in physics, when what is under investigation is most naturally taken to be an a priori matter: the coherence of a connective with given inferential properties. This is not at all to deny that the ‘quantum machines’ described in Deutsch et al. (2000) (or Chiara, Giuntini, and Greechie 2004, 257–259) may help us get a feel for the connective in  question.[44]