The Department of Philosophy: Colloquium — Eric Schliesser's "Spinoza and the Newtonians on Motion and Matter (and God, of Course)"

Synopsis of Eric Schliesser’s “Spinoza and the Newtonians on Motion and Matter (and God, of Course)”: 

The purpose of this paper is three-fold. First, I document a battery of arguments that were generated by the first generation of English critics of Spinoza: Henry More and, especially, Samuel Clarke. These arguments focus on the perceived deficiency of Spinoza’s treatment of motion. These arguments are offered as internal and external criticisms to Spinoza’s system. The internal criticisms are two-fold: i) Spinoza cannot account for the origin of motion from within his system; ii) Spinoza offers contradictory analysis of motion. Both criticisms are connected to Spinoza’s views on the nature of matter. The external criticisms can also be distinguished: i) Spinoza’s treatment of motion neither lends itself to (mathematical) natural philosophy nor to some of its detailed empirical claims; ii) the particular motion(s) exhibited in the world require(s) a different conception of God than Spinoza offers. It is no surprise that in Clarke’s A Demonstration of the Being and Attributes of God (1704), the empirical success of Newtonian natural philosophy is explicitly used in various arguments against Spinoza

Second, I show that even though Newton does not explicitly mention Spinoza in the Principia, he added an argument to the General Scholium (added to the second, 1713 edition of the Principia) that is identical to one of Clarke’s arguments in A Demonstration. Informed readers of the Principia will recognize the target. (Moreover, it turns out that some of the other changes to second edition of the Principia can be related to Clarke’s treatment of providence.) I provide evidence that the leading Newtonian of the Scottish Enlightenment, Colin MacLaurin, relied on the Clarke’s arguments and extended such against Spinoza by showing how Spinoza’s views on motion, conservation laws, and the vacuum are all intertwined. As an aside, Clarke and MacLaurin sensitize us to Spinoza’s critical remarks about mathematical natural philosophy.

Third, I turn to a more sympathetic treatment of Spinoza’s views on motion. In particular, by drawing on Toland’s Letters to Serena, I show that Spinoza’s most sophisticated defenders recognized that the Newtonians had hit a significant target. However, I show that Toland also remotivates Spinoza’s matter theory with resources that can salvage Spinozism in an age where Newtonian mathematical science rules supreme.