Extension
Extension is the physical attribute of substance — the world of bodies, motion, and spatial reality.
In depth
Under Extension, substance expresses itself as physical bodies occupying space, subject to the laws of motion. Your body, the earth, and every material object are modes of Extension. Crucially, Extension is not inferior to Thought — both attributes are equally fundamental expressions of God/Nature.
Why it matters
Spinoza gives the physical world full ontological dignity. Matter is not fallen or lesser — it is God expressing itself physically, just as Thought is God expressing itself mentally.
Source references
- Ethics II.P1-P2