Rene Descartes: March – February Father of Modern Philosophy Attempts to reconcile the new scientific method with traditional metaphysics. Rationalism, Dualism.

Descartes’ Skeptical Observations 1. Several years have now past since I first realized how many were the false opinions that in my youth I took to be true, and thus how doubtful were all the things that I subsequently built upon these opinions. 2. Whatever I had admitted...as most true I took in from the senses...; however I noticed that they sometimes deceived me.

Descartes’ Dreams and Demons 3. This all seems as if I do not recall having been deceived by similar thoughts in my dreams. As I consider these cases I see there are no definite signs to distinguish being awake from being asleep. 4. Suppose an evil genius has directed his entire effort to misleading me. The heavens, the air, the earth, the colors, shapes, sounds, and all external things would be nothing but deceptive games of my dreams.

Qualitative indistinguishability of vat experiences and sense experiences. Oh Drat, I’m a brain in a vat!

Cartesian Certainty At length I am forced to admit that there is nothing among the things I once believed to be true, which it is not possible to doubt, not for reasons of frivolity...but because of valid and considered arguments. Med. II: Even if a demon deceives me, “I am, I exist,” is true whenever I doubt it. No perceptual experience is required to obtain this knowledge. “My body exists” cannot be known with certainty. So I am a thinking thing that may have a body.

Non-sensory knowledge of body. This piece of bee’s wax: tastes sweet, smells flowery; feels hard and cold, squeezes when I press it, makes sound when I tap it. I hold it near the fire: taste is gone; smell evaporates; color changes, shape is gone; size increases, makes no sound when tapped. Yet I know it is the same wax. So my knowledge of the wax is is an intuition of the mind occasioned by (but not based on) perception.