  This paper presents a minimal formulation of nonrelativistic quantum
mechanics, by which is meant a formulation which describes the theory in a
succinct, self-contained, clear, unambiguous and of course correct manner. The
bulk of the presentation is the so-called \lq microscopic theory' (MIQM),
applicable to any closed system $S$ of arbitrary size $N$, using concepts
referring to $S$ alone, without resort to external apparatus or external
agents. An example of a similar minimal microscopic theory is the standard
formulation of classical mechanics, which serves as the template for a minimal
quantum theory. The only substantive assumption required is the replacement of
the classical Euclidean phase space by Hilbert space in the quantum case, with
the attendant all-important phenomenon of quantum incompatibility. Two
fundamental theorems of Hilbert space, the Kochen-Specker-Bell theorem and
Gleason's theorem, then lead inevitably to the well-known Born probability
rule. For both classical and quantum mechanics, questions of physical
implementation and experimental verification of the predictions of the theories
are the domain of the macroscopic theory, which is argued to be a special case
or application of the more general microscopic theory.
