Why Spinozism looks false: introspection, folk psychology, and the Cartesian illusion of belief

According to the Spinozan theory of belief formation, our beliefs are the automatic outputs of a subpersonal mental process that is activated whenever a mental system tokens a truth-apt proposition. Spinozism finds support across a substantial body of experimental evidence, but it faces an underappreciated objection. If the Spinozan theory is true, why does it seem so obviously false? When we try to introspect on our belief formation process, it looks Cartesian. We seem able to comprehend a proposition and then deliberate about its truth prior to believing or disbelieving it. The Cartesian character of our doxastic phenomenology presents us with an inner mental life where we exercise indirect voluntary control over what we believe. This Cartesian phenomenology is pervasive and so deeply embedded in our shared folk psychology that it creates an explanatory burden for the Spinozan theory. In this paper, I argue that the Spinozan can meet this burden by providing an explanation of Cartesian phenomenology and folk psychology. The Cartesian phenomenology is an illusion generated by the introspective inaccessibility of subpersonal processes and folk psychology has a Cartesian character because it is built from introspective reports that misrepresent the temporal ordering of the belief formation process.