The Res Cognitas Argument

To established a new foundational beliefs from his very existence, first he need to know himself so Rene Descartes ask the questions "What am I?"

Properties I previously have (before the skeptical hypothesis)

a. Body — physical properties

b. Nourishment — growth

c. Locomotion — movement

d. Sensing — seeing, feeling, etc.

e. Thinking

Premise 1: I can doubt that I have physical body, nourishment, locomotion, and sensing. (eliminated by the Skeptical argument from Meditation 1)

Premise 2: But I cannot doubt my existence when I'm Thinking

Conclusion 1: So I am a "Thinking thing".