While it might be a little extreme to refer to Descartes as the anti-christ, I think we’d all agree that it’s safe to say that he doesn’t deserve to even come close to sainthood.
Especially in the instance of Descartes, it is important to remember that ideas have consequences.
“Cogito ergo sum,” is such an example. Whether he was speaking of epistemology or ontology is almost not the point.
Descartes, as a rationalist, laid a pretty strong foundation for many, many philosophical errors which were to come (think Rousseau… Nietzsche. Jacques Maritain, a 20th-century Thomistic philosopher, wrote a book on this idea, called “The Three Reformers,” basically the three men who laid the foundation for modern thought which rejects faith and reason & Christian ideals. (The 3 were Luther, Descartes, and Rousseau))
Faith is dismissed as irrational in Enlightenment philosophy, quite different from the Catholic tradition of faith and reason. And besides, focusing on the passions as good in themselves, as Descartes does, is, at the very least, a distraction from the Christian life.
Also, I don’t understand anywhere how Descartes dualist philosophy–the separation of body from soul–could ever possibly fit with any Catholic concept of the person. The human person is a unified one, who exists not because he thinks but because he is created by God.
I am by no means an expert philosopher… just felt the need to respond to the absurd idea of St. Rene!