  Entropic Dynamics is a framework in which dynamical laws are derived as an
application of entropic methods of inference. No underlying action principle is
postulated. Instead, the dynamics is driven by entropy subject to the
constraints appropriate to the problem at hand. In this paper we review three
examples of entropic dynamics. First we tackle the simpler case of a standard
diffusion process which allows us to address the central issue of the nature of
time. Then we show that imposing the additional constraint that the dynamics be
non-dissipative leads to Hamiltonian dynamics. Finally, considerations from
information geometry naturally lead to the type of Hamiltonian that describes
quantum theory.
