 This debate is far from settled. The laws of classical electrodynamics, the Maxwell-Lorentz equations, imply a wave equation, which is a time-reversal invariant hyperbolic equation of motion and is standardly solved using the Green’s functions formalism. Thus, the disagreement is partly a disagreement over the question whether the radiation field’s causal or retarded Green’s function captures important features of how charged particles and electromagnetic fields interact that are not properly captured by the “anti-causal” or advanced Green’s functions.