  We address a long-standing debate over whether classical magnetic forces can
do work, ultimately answering the question in the affirmative. In detail, we
couple a classical particle with intrinsic spin and elementary dipole moments
to the electromagnetic field, derive the appropriate generalization of the
Lorentz force law, show that the particle's dipole moments must be collinear
with its spin axis, and argue that the magnetic field does mechanical work on
the particle's elementary magnetic dipole moment. As consistency checks, we
calculate the overall system's energy-momentum and angular momentum, and show
that their local conservation equations lead to the same force law and
therefore the same conclusions about magnetic forces and work. We also compute
the system's Belinfante-Rosenfeld energy-momentum tensor.
