[en] In this paper the interaction of the pion with a finite nucleus is examined within the context of a field-theoretic many-body problem. The qualitative features of the interaction of the pion with the nucleon and with the nucleus are reviewed. A contemporary momentum-space approach to this problem is derived and compared with other approaches. Some of the important features incorporated in the momentum-space approach are: the use of Lorentz invariant kinematics, invariant normalizations and phase space, and the use of the invariant amplitude, a dynamic model of the pion-nucleon interaction which produces reasonable off-shell properties, and the performance of the fermi-averaging integral (delta propagation) by utilizing relativistic three-body recoupling coefficients. Results are presented for elastic scattering. Some directions for future work are discussed and the importance for an improved interplay between the various theoretical models is stressed. In addition, several exciting examples of recent experimental work are summarized