 If we put aside scruples about “measurement” as a primitive term in physical theory, and accept a principled distinction between “testable” and non-testable properties, then the fact that \(L(\mathbf{H})\) is not Boolean is unremarkable, and carries no implication about logic per se. Quantum mechanics is, on this view, a theory about the possible statistical distributions of outcomes of certain measurements, and its non-classical “logic” simply reflects the fact that not all observable phenomena can be observed simultaneously. Because of this, the set of probability-bearing events (or propositions) is less rich than it would be in classical probability theory, and the set of possible statistical distributions, accordingly, less tightly constrained. That some “non-classical” probability distributions allowed by this theory are actually manifested in nature is perhaps surprising, but in no way requires any deep shift in our understanding of logic or, for that matter, of probability.