Descartes’s Argument for Uncertainty

Descartes’s Argument for Uncertainty 1. All previously held conceptions must be regarded as uncertain. a. Some previous conceptions were built on false opinions, or potentially false opinions and are therefore uncertain. b. All previous conceptions have been obtained from or through the senses, which guarantees their uncertainty. I. The senses have deceived in the past in cases of a small or distant thing, and could therefore do so again. II. The senses often deceive those who are mad, although it would make one equally as mad to consider this reason for doubting their own perceptions. III. It’s possible to be dreaming an absurd or realistic dream, yet convinced that the senses are experiencing wakefulness. c. Even simple and universal things (size, shape, arithmetic, geometry, etc) are uncertain. I. It’s possible that an omnipotent God is deceiving us in respect to these things. In this case, all things are uncertain. II. Others are sometimes mistaken even though they believe they’re certain, so anyone could be mistaken. III. If an omnibenevolent creator prevents deception, we wouldn’t have been created in a way prone to being deceived. IV. If there is no omnipotent creator, deception is even more likely, as originating from a less powerful cause makes imperfect judgment more likely. d. All things are uncertain I. To avoid previous prejudices leading to error, one should completely turn their back on previous opinions. II. It’s possible a supremely powerful evil deceiver exists, dedicating his entirety to deception, making all things subject to doubt, and therefore