  A critical reconsideration of the EPR (Einstein-Podolsky-Rosen) paper shows
that the EPR argument can be developed without using the concept of `element of
physical reality', thus eliminating any philosophical element in the logical
chains of the paper. Deprived of its philosophical ornament, the EPR argument
plainly reduces to require what quantum mechanics can not do: to assign
definite values to two incompatible physical quantities. Hidden variables
theories built up according to Bell - type theorems are formulated on the basis
of the assumption that the locality condition implies the statistical
independence between two measurements space - like separated. This assumption
is valid only with the additional one that statistical dependence between two
measurements requires a causal connection between them. This additional
assumption rules out the possibility that statistical dependence may due to an
intrinsic property of the physical system under study. Therefore, hidden
variables theories are built up with a restriction which leads them to be
disproved by experiment. Quantum mechanical non - locality, invoked for
describing EPR - type experiments, is strictly connected to the hypothesis (NDV
hypothesis) according to which the twin photons of entangled pairs do not have
a definite polarization before measurements. Both hypotheses are used only for
describing EPR experiments and not for making predictions. Therefore, they can
be dropped without reducing the predictive power of quantum mechanics
concerning entangled photons pairs. Furthermore, both hypotheses can be
experimentally tested by a modification of a standard experimental apparatus
designed for studying entangled photons pairs.
