Single Idea 5615

[catalogued under 26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension]

Full Idea

Extension and impenetrability together constitute the concept of matter.

Gist of Idea

Extension and impenetrability together make the concept of matter

Source

Immanuel Kant (Critique of Pure Reason [1781], B646/A618)

Book Reference

Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.576


A Reaction

Descartes had settled for extension alone. Kant's simple claim is probably now just a historical footnote, as we would now turn to physicists to define matter. Extension might survive, but impenetrability is not a key notion in quantum mechanics.