As I have discussed here before (notably in connection with the Vienna Circle), I believe there are limits to the applicability of the law of the excluded middle. One example: one can say with some plausibility that as recently as 1990 the validity of Fermat's last theorem was outside the scope of the law. The answer was not only not known, there was no clear procedure for solving it. So ... it was neither true nor false until such a proof had been created (not discovered, if one is going to take this view: created). Likewise with the Riemann Hypothesis, still unsolved to this day, though it helpfully provides us with a striking image above. A gentlemen who regularly comments on math issues in Quora wrote recently, "There are several fields of mathematics which only make sense on the premise that the Riemann Hypothesis is true, and a handful of others which only make sense on the premise that it is false." My point though is that n...