 Perhaps McTaggart’s skepticism about the usefulness of empirical inquiry for metaphysical investigations is why his twentieth-century works are almost entirely devoid of commentary on the revolutions occurring in fundamental physics. (Einstein is mentioned exactly once in both volumes of The Nature of Existence, briefly and in passing in section 369 of the second volume.) Unlike some of his near-contemporaries, such as A.N. Whitehead and Bertrand Russell, McTaggart proceeds as if he were blithely unaware of the potential for interplay between physics and  philosophy.[7]