  This paper discusses questions concerning the foundations of quantum
mechanics (entanglement, wave collapse, irreversibility) with reference to the
issues raised during a Minisymposium held in Helsinki, 1.6-3.6 in 1992, where A
Shimony, A Peres and B d'Espagnat were invited to lecture. The measurement
problem is related to the phenomenon of irreversibility which is known not to
follow from any fundamental theory; e.g., the law of exponential decay does not
follow from the Schr\"odinger equation in senso stricto. The approximations
that lead to irreversibility are related to some form of ''forgetting'', or
coarse graining. Some approaches to the question, why these approximations can
be justified, are reviewed. The paper also discusses dynamical reduction
schemes and it is suggested, that the corresponding non-linear modifications of
the Schr\"odinger equation -- which lead to non-conservation of energy -- are
actually ''effective'' Schr\"odinger equations for open systems (in analogy
with the ''effective'' Lagrangians in QFT). Thus these modifications should be
derived from a fundamental theory of interactions. The paper ends with some
brief comments on the mind-body question in the quantum mechanical context. A
postscript has been added (2006).
