 Bohmian mechanics is a counterexample to the claims of von Neumann and Born. Thus von Neumann’s argument must be wrong. In fact, according to John Bell, von Neumann’s assumptions (about the relationships among the values of quantum observables that must be satisfied in a hidden-variables theory, see Bell 1966) are so unreasonable that the “the proof of von Neumann is not merely false but foolish!” (Mermin 1993: 805, fn 8, quoting an interview in Omni, May, 1988: 88). Nonetheless, some physicists continue to rely on von Neumann’s proof. 