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Single Idea 5615

[filed under theme 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 Ref

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.

The 8 ideas with the same theme [matter is just whatever occupies a space]:

16687 Bodies are three-dimensional substances [Aquinas]
16684 Impenetrability only belongs to the essence of extension [Descartes]
16601 Matter is not hard, heavy or coloured, but merely extended in space [Descartes]
6518 Matter can't just be Descartes's geometry, because a filler of the spaces is needed [Robinson,H on Descartes]
13185 Even if extension is impenetrable, this still offers no explanation for motion and its laws [Leibniz]
16683 Leibniz eventually said resistance, rather than extension, was the essence of body [Leibniz, by Pasnau]
5615 Extension and impenetrability together make the concept of matter [Kant]
6519 Locke's solidity is not matter, because that is impenetrability and hardness combined [Robinson,H]