... there was a great obstacle to this delayedaction-at -a- distance theory: namely, if a radiating electron, say inan atom or an antenna, were not acted upon at all by the field thatit radiated, then ... independently anticipated the absorber idea.6W. Yourgrau and S. Mandelstam give an excellent analytic historical account inVariational Principles in Dynamics and Quantum Theory (Saunders, Philadelphia, ... electromagneticinteractions without fields, except as an auxiliary device, the ques-tion arises as to how to make a corresponding quantum theory .To treat a classical system of interacting particles, there are avail-able...