Relativistic nuclear field theories are being studied as an alternative to the description of the nucleus as a classical quantum many-body system. Particular effort is being directed at the problem of accurately calculating quantum corrections to the mean field equations and identifying signatures of such corrections in experimental data. The problem of correctly incorporating the pion into quantum hadrodynamics (QHD), where the fundamental constituents are taken as baryons and mesons, is also a major objective. This problem is closely related to the calculation of quantum corrections, and it provides a vehicle for exploring several nonperturbative approaches. This research is directed toward the development of a description of the nucleus which properly incorporates subnucleonic particles and interactions discovered in high reactions and seeks to unify nuclear physics to the unifying theory of quantum chromodynamics.