  Quantum mechanics is derived from the principle that the universe contain as
much variety as possible, in the sense of maximizing the distinctiveness of
each subsystem.
  The quantum state of a microscopic system is defined to correspond to an
ensemble of subsystems of the universe with identical constituents and similar
preparations and environments. A new kind of interaction is posited amongst
such similar subsystems which acts to increase their distinctiveness, by
extremizing the variety. In the limit of large numbers of similar subsystems
this interaction is shown to give rise to Bohm's quantum potential. As a result
the probability distribution for the ensemble is governed by the Schroedinger
equation.
  The measurement problem is naturally and simply solved. Microscopic systems
appear statistical because they are members of large ensembles of similar
systems which interact non-locally. Macroscopic systems are unique, and are not
members of any ensembles of similar systems. Consequently their collective
coordinates may evolve deterministically.
  This proposal could be tested by constructing quantum devices from entangled
states of a modest number of quits which, by its combinatorial complexity, can
be expected to have no natural copies.
