文档介绍：Chapter 28
Metaphysical Problems in the Foundations
of Quantum Mechanics
Abner Shimony
I propose to summarize a certain line of development in the foundations of quantum
mechanics-partly theoretical and partly experimental-and to examine its philo-
sophical implications. The major ideas of this line of development are fairly simple and
can be conveyed plicated calculations. In order to avoid arousing expecta-
tions which cannot be fulfilled, I wish to say in advance that the philosophical implica-
tions which will be drawn from analyzing the foundations of quantum mechanics are
not unequivocal and unqualified. They take the form rather of a disiunction: there
appear to be only two options left open by the results of experiments, and we cannot
at the present time say which option is correct. I think we can confidently say that
either option is momentous, metaphysically or epistemologically; we must recognize
either that the intrinsic properties of the real world are very strange indeed, or that
scientific theories say much less about the intrinsic properties of things than scientists
monly assumed.
I. Data and Resulting Problems
Let us begin our analysis by looking at some of the elementary formalism of quantum
mechanics. It will be convenient to use the concept of the "state" of a physical
system, even though it is a subtle concept that may have to be refined as a result of
analysis. Roughly, a state of a physical system is a maximal specification of it-., a
specification of the contingencies of the system such that nothing more can be said of
it that is not either redundant or contradictory. Quantum mechanics assumes that the
set of possible states of a physical system obeys the superposition principle, which can
roughly be explained as follows.' Suppose F is a dynamical variable of the system
(often called an "observable") such as the position of the system along a certain axis.
Let u, be a state of the syst