  Quantum particles and classical particles are described in a common setting
of classical statistical physics. The property of a particle being "classical"
or "quantum" ceases to be a basic conceptual difference. The dynamics differs,
however, between quantum and classical particles. We describe position, motion
and correlations of a quantum particle in terms of observables in a classical
statistical ensemble. On the other side, we also construct explicitly the
quantum formalism with wave function and Hamiltonian for classical particles.
For a suitable time evolution of the classical probabilities and a suitable
choice of observables all features of a quantum particle in a potential can be
derived from classical statistics, including interference and tunneling.
Besides conceptual advances, the treatment of classical and quantum particles
in a common formalism could lead to interesting cross-fertilization between
classical statistics and quantum physics.
