 
Summary: Published in the Proceedings of the International Symposium on the Foundations of Modern
Physics 1993, Helsinki, Finland, ed. Hyvonen, T., World Scientific, Singapore, 35  56.
Quantum Probability, the Classical Limit and NonLocality.
Diederik Aerts, Thomas Durt and Bruno Van Bogaert,
FUND, Free University of Brussels, Pleinlaan 2,
B1050 Brussels, Belgium, diraerts@vub.ac.be
ABSTRACT.
We investigate quantum mechanics using an approach where the
quantum probabilities arise as a consequence of the presence of fluc
tuations on the experimental apparatuses. We show that the full
quantum structure can be obtained in this way and define the classi
cal limit as the physical situation that arises when the fluctuations on
the experimental apparatuses disappear. In the limit case we come
to a classical structure but in between we find structures that are nei
ther quantum nor classical. In this sense, our approach not only gives
an explanation for the nonclassical structure of quantum theory, but
also makes it possible to define, and study the structure describing
the intermediate new situations. By investigating in which way the
nonlocal quantum behaviour disappears during the limiting process
we can explain the 'apparent' locality of the classical macroscopical
