This book describes a promising approach to problems in the foundations of quantum mechanics
including the measurement problem. The dynamics of ensembles on configuration space is shown
here to be a valuable tool for unifying the formalisms of classical and quantum mechanics for
deriving and extending the latter in various ways and for addressing the quantum measurement
problem. A description of physical systems by means of ensembles on configuration space can be
introduced at a very fundamental level: the basic building blocks are a configuration space
probabilities and Hamiltonian equations of motion for the probabilities. The formalism can
describe both classical and quantum systems and their thermodynamics with the main difference
being the choice of ensemble Hamiltonian. Furthermore there is a natural way of introducing
ensemble Hamiltonians that describe the evolution of hybrid systems i.e. interacting systems
that have distinct classical and quantum sectors allowing for consistent descriptions of
quantum systems interacting with classical measurement devices and quantum matter fields
interacting gravitationally with a classical spacetime.
