 Finally, in the light of the foregoing discussion, Lewis’s view is open to an objection from physics: there is no absolute fact of the matter about the distance between the electron and proton independently of facts about the physical fields more generally, e.g., the electromagnetic field and the electron field, i.e., facts concerning what is happening elsewhere. So the distance relation of the electron and fusion cannot supervene upon the intrinsic character of the proton-electron fusion. It follows that distance relations cannot be external in Lewis’s sense.