 The claim that matter has not even an accidental power of self-motion was central to Clarke’s attempt to exhibit the manifest activity of God in the Newtonian world and refute Spinozism (Schliesser 2012, 443–449). The claim was radical for the time and elicited many responses. Collins, in a letter to John Trenchard, was angered and unimpressed by Clarke’s arguments, which was a common reaction for the growing number of freethinkers (Jacob 1977; 20). Andrew Baxter (1733, with an important appendix added in 1750) would later extend Clarke’s arguments against self-motion, showing that they apply to ether as well as matter, at a time when ether theories had gained popularity as interpretations of Newton and as hypotheses for explaining gravity.