Action at a distance: From Newton’s gravity to quantum theory

Abstract Isaac Newton’s theory of gravity seems to postulate action at a distance. Two distant massive bodies act on one another gravitationally instantaneously without a causal mechanism to mediate the action. This paper will argue that a strategy found in the Principia that allows Newton’s theory to be explanatory without providing a causal explanation can be extended to the quantum case. However, while causal action at a distance can be avoided, the explanatory cost of avoiding any form of nonlocality is higher in the quantum case than in the case of Newton’s theory of universal gravitation.