  We raise the issue whether conventional quantum mechanics, which is not a
hidden variable theory in the usual Jauch-Piron's sense, might nevertheless be
a hidden variable theory in the sense recently conjectured by G. 't Hooft in
his pre-quantization scheme. We find that quantum mechanics might indeed have a
fully deterministic underpinning by showing that Born's rule naturally emerges
(i.e., it is not postulated) when 't Hooft's Hamiltonian for be-ables is
combined with the Koopmann - von Neumann operatorial formulation of classical
physics.
