Full Idea
Without the notion of substance, according to Spinoza, thought itself becomes impossible.
Gist of Idea
Spinoza implies that thought is impossible without the notion of substance
Source
report of Baruch de Spinoza (The Ethics [1675]) by Roger Scruton - Short History of Modern Philosophy §5.2
Book Reference
Scruton,Roger: 'A Short History of Modern Philosophy' [ARK 1985], p.52
A Reaction
Spinoza's strategy here looks like the right way to approach metaphysics. To what extent is it possible to change our conceptual scheme? Quine seems to imply that there is no limit; Davidson seems to imply that it is impossible.