  These lectures explain that comparisons between experiment and theory can
expose the impact of running couplings and masses on hadron observables and
thereby aid materially in charting the momentum dependence of the interaction
that underlies strong-interaction dynamics. The series begins with a primer on
continuum QCD, which introduces some of the basic ideas necessary in order to
understand the use of Schwinger functions as a nonperturbative tool in hadron
physics. It continues with a discussion of confinement and dynamical symmetry
breaking (DCSB) in the Standard Model, and the impact of these phenomena on our
understanding of condensates, the parton structure of hadrons, and the pion
electromagnetic form factor. The final lecture treats the problem of grand
unification; namely, the contemporary use of Schwinger functions as a
symmetry-preserving tool for the unified explanation and prediction of the
properties of both mesons and baryons. It reveals that DCSB drives the
formation of diquark clusters in baryons and sketches a picture of baryons as
bound-states with Borromean character. Planned experiments are capable of
validating the perspectives outlined in these lectures.
