The theory of direct interparticle action is equivalent

In 1949, John Wheeler and Richard Feynman suggested something radical:

particles don’t act on themselves, only on each other ✍️

"The theory of direct interparticle action is equivalent, not to the usual field theory, but to a modified or adjunct field theory, in which:

(1) the motion of a given particle is determined by the sum of the fields produced by—or adjunct to—every particle other than the given particle.

(2) the field adjunct to a given particle is uniquely determined by the motion of that particle, and is given by half the retarded plus half the advanced solution of the field equations of Maxwell for the point charge in question.

This description of nature differs from that given by the usual field theory in three respects:

(1) There is no such concept as “the” field, an independent entity with degrees of freedom of its own.

(2) There is no action of an elementary charge upon itself and consequently no problem of an infinity in the energy of the electromagnetic field.

(3) The symmetry between past and future in the prescription for the fields is not a mere logical possibility, as in the usual theory, but a postulational requirement.

– John Archibald Wheeler and Richard P. Feynman