  A four part series of lectures on the connection of statistical mechanics and
quantum field theory. The general principles relating statistical mechanics and
the path integral formulation of quantum field theory are presented in the
first lecture. These principles are then illustrated in lecture 2 by a
presentation of the theory of the Ising model for $H=0$, where both the
homogeneous and randomly inhomogeneous models are treated and the scaling
theory and the relation with Fredholm determinants and Painlev{\'e} equations
is presented. In lecture 3 we consider the Ising model with $H\neq 0$, where
the relation with gauge theory is used to discuss the phenomenon of
confinement. We conclude in the last lecture with a discussion of quantum spin
diffusion in one dimensional chains and a presentation of the chiral Potts
model which illustrates the physical effects that can occur when the Euclidean
and Minkowski regions are not connected by an analytic continuation. (To be
published as part of the Proceedings of the Sixth Annual Theoretical Physics
Summer School of the Australian National University which was held in Canberra
during Jan. 1994.)
