 Throughout Letters, Norris defends his occasionalism against Astell’s critiques, which were based on Cambridge Platonist views about the nature of the mind–body union. In the appendix—written after Norris convinced Astell to allow him to publish the letters as a volume—Astell presents two final criticisms of Norris’s account. First, occasionalism makes much of God’s creation vain: if God is the efficient cause of all of our sense perceptions, then his creation of material objects is superfluous, for they play no direct role in our sense perceptions (Astell, Norris 1695, 278–80). Second, occasionalism offends God’s majesty, for according to it he repeatedly interferes in creation in order to move bodies and create mental events. (Astell, Norris 1695, 278).  See O’Neill (2007) for a history of these arguments in St. Thomas’ critiques of medieval Islamic occasionalists.