Skepticism About the External World

The book questions the reality of external objects, arguing that our ideas of extension, solidity, and matter are ultimately derived from perceptions and may lack independent existence.

By reducing substance to a collection of qualities, Hume undermines the notion of an unknown substratum, a key skeptical move.

The rejection of the idea of a vacuum and the limitation of our ideas to what is derived from impressions demonstrates a skeptical stance towards concepts that go beyond our perceptual experience.

Hume challenges common assumptions about the nature of objects, suggesting that our perceptions may not accurately represent their true divisibility.

By questioning the infinite divisibility of space and time, Hume challenges the nature of external reality and our ability to know it.