  We examine historic formulations of the spin-statistics theorem from a point
of view that distinguishes between the observable consequences and the
``symmetrization postulate''. In particular, we make a critical analysis of
concepts of particle identity, state distinguishability and permutation, and
particle ``labels''. We discuss how to construct unique state vectors and the
nature of the full state descriptions required for this -- in particular the
elimination of arbitrary $2\pi$ rotations on fermion spin quantization frames
and argue that the failure to do this renders the conventional symmetrization
postulate (and previous ``proofs'' of it) at best {\em incomplete}.
  We discuss particle permutation in a general way for any pairs of particles,
whether identical or not, and make an essential distinction between exchange
and pure permutation. We prove a revised symmetrization postulate that allows
us to construct state vectors that are naturally symmetric under pure
permutation, {\em for any spin}. The significance of particle labels (which, in
the exchange operation, are not permuted along with other variables) is then
that they stand in for any asymmetry (order dependence) that is present in the
full state descriptions necessary for unique state vectors but not explicit in
the regular state variables. {\em The exchange operation is then the physical
transformation that reverses any asymmetry implicit in the labels}.
  We point out a previously unremarked geometrical asymmetry between all pairs
of particles that is present whenever we choose a common frame of reference. We
compute the exchange phase for various state vectors using different spin
quantization frames, and prove the Pauli Exclusion Principle and its
generalization to arbitrary spin.
