The correspondence of René Descartes and Princess Elisabeth of Bohemia

Always felt Descartes kind of cheated himself with his very categorical denounciation of the body and the animals as mere thoughtless automatons.

Leibniz and Spinoza (the other 2 of the 3 great 16th century rationalists) have more nuanced views, esp Spinoza who in his Ethica said something like: Descartes was a very bright man who non the less fooled himself with the idea of the pineal gland as seat of the soul. Etc

The Cartesian metaphysical tradition has had an enormous impact on our thinking to this today, often without us realizing it. Materialism itself, which opposes the dualism of Descartes, only makes sense within the Cartesian paradigm. Far from wholly rejecting his metaphysics, it merely rejects the immateriality of the mind, preserving the impoverished view of matter that Descartes held to be true. Indeed, Cartersianism frames much of the discussion in contemporary philosophy of mind, determining what the problems are and what the solutions might be, if there are any. Philosophers committed to that metaphysics are inevitably forced into dualism, panpsychism or eliminativism. All three suffer from serious issues, the worst of which is eliminativism, the most Procrustean and incoherent of the bunch.

Ultimately, Descartes did not disprove the Aristotelian and Scholastic metaphysics[0]. He merely dismissed it.

[0] Moliere's famous bit in "The Imaginary Invalid" fails because, while the appeal to dormitive powers is minimally informative, it is not tautological.

Most times I see Descartes quoted it is with the paraphrase: "I think therefore I am" which is a really poor abstraction of his 6 Meditations.