effect and referring to the vector potential $\mathbf{A}$ and the magnetic field $\mathbf{B}$, he wrote [@5]: “$\mathbf{A}$ is as real as $\mathbf{B}$-realer, whatever that means.”

We think that the speculative idea raised by Feynman of introducing potentials before fields is pedagogically interesting and deserves to be explored. In this sense it is pertinent to say that in the traditional presentation of Maxwell’s equations appearing in textbooks, potentials are introduced using the homogeneous Maxwell’s equations. The electric and magnetic fields expressed in terms of the scalar and vector potentials are then used in the inhomogeneous Maxwell’s equations, obtaining explicit retarded forms of these potentials. The reversed idea of introducing first retarded potentials satisfying wave equations and then deriving the homogeneous Maxwell’s equations does not seem to have been explored so far, at least in the standard literature available to us. However, we believe that the idea exploring alternative presentations of Maxwell’s equations is important for pedagogical and conceptual reasons.

In this paper we suggest that the “other principle” to obtain the inhomogeneous Maxwell’s equations mentioned by Feynman may be the principle of local charge conservation represented by the continuity equation. We show how a heuristic procedure involving formal operations on the 