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  • Joseph Simpson thinks this is interesting:

René Descartes is famous not just for inventing Cartesian mathematics, which at the time was a stunning unification of algebra and geometry. He is also well-known for making a pretty good stab of answering the question “How do I know something is true?”—a question that has kept generations of philosophers happily employed and does not necessarily involve dead sheep (which will perhaps disturbingly be a central feature of the next section), unless you really want it to. Descartes rejected the answers proposed by the Ancient Greeks, which are ethos (roughly, “because I told you so”), pathos (“because it would be nice”), and logos (“because it makes sense”), and set about figuring it out for himself with a pencil and paper.

From

Cover of 3D Math Primer for Graphics and Game Development, 2nd Edition, 2nd Edition

Note

This may be one of the best descriptions of Descartes I have ever seen