In his work, Descartes is a sincere and motivated theist. God plays a role in Cartesian metaphysics. Descartes also contended that the soul is immortal. He considered himself to be a faithful Christian and a devout Roman Catholic. He took pains to show that his philosophy could be harmonized with the teachings and philosophy of the Roman Catholic church.
Yet the church of his day found fault with Descartes. Some scholars accused him of deism, while others asserted that by deducing foundational truths rationally, he had made God contingent upon reason.
Not only the Roman Catholic church, but rather also other Christians as well, objected to various aspects of Cartesian thought. Diatribes against Descartes became a staple in folk piety and popular religion. The following passage from Mike Breen is an example:
We have become so acculturated in our Cartesian, Western world that we believe knowing about something and knowing something are the same thing. What we have managed to do is teach people about God. Teach them about prayer. Teach them about mission. The point isn’t that they would just know about it but to know it.
The irony is, of course, that Descartes seems to have understood himself as a sincere Christian, and seems to have thought that he had found a way simultaneously to serve the church, to serve the faith, and to serve theology. What was the disconnect? Why wasn’t Descartes enthusiastically embraced by his church and by his fellow Christians?
To be sure, there were some Christians who did eagerly espouse Cartesian thought. A number of philosophers, theologians, and other scholars saw Cartesian philosophy as thoroughly compatible with conventional Christian faith, and these thinkers adopted Cartesian philosophy.
But Cartesianism never quite established itself in the mainstream of popular Christianity.
The reason for Cartesianism’s lack of acceptance is found, not necessarily in what Cartesianism is, but rather in how it was and is perceived.
The image of Cartesian thought in the public may be more of a caricature and less of an accurate reading of Descartes and his texts. The concerns of folk piety saw Cartesianism as lacking, or at least de-emphasizing, the personhood and agency of God. The Cartesian God was seen as something of an abstract principle, a bundle of logical axioms and mathematical equations, and an impersonal force.
Descartes did not seem to meet the need for a God with emotions, desires, memories, intentions, and other aspects of personhood. While Cartesianism certainly included God’s actions, it seemed to omit the centrality of God’s volitional action.
How accurately did the popular imagination grasp Descartes? While his philosophical writings don’t emphasize God’s personhood and agency, they also do not exclude it. It would be possible to subscribe to Cartesian metaphysics and at the same time endorse a theology which featured a fully personal God.
In his writings, Descartes seems to concentrate on God’s existence and God’s role in the metaphysical principles of the universe. What were his own private thoughts or beliefs on the matter? Did Descartes conceive of God as having personhood and agency, and simply omit to mention this in his texts?
