 Moreover, while Hume and Newton both appeal to the authority of “experience”, there are further serious tensions between Hume’s account of causation and the contents of Newton’s natural philosophy. For Newton, the behavior of the moon in its orbit and that of, say, apples falling on the earth have the same cause: namely, the force of gravity, or weight, towards the earth (Principia, Book III, Scholium to Proposition IV, Theorem IV). This conflicts with the contiguity requirement, which Hume considers “essential” to “causation” (THN 1.3.2.6). It is hard to see how contiguity could be made consistent with the universal nature of attraction. The most distant particles of the universe attract each other. (The contiguity requirement notably disappears in EHU.) More important, according to Newton the acceleration produced by the exercise of a force is simultaneous with that exercise—thus defying temporal priority (Smeenk &amp; Schliesser 2013). Hume claims that temporal priority of the cause is “of no great importance” (THN 1.3.2.8), yet it appears explicitly or implicitly throughout his treatment of causation. Be that as it may, Hume explicitly attacks the possibility of an effect being simultaneous with its cause (THN 1.3.2.7–8; Ryan 2003).