Full Idea
If a triangle could speak it would say that God is eminently triangular.
Gist of Idea
A talking triangle would say God is triangular
Source
Baruch de Spinoza (Letters to Blijenburgh [1665], 1665), quoted by Matthew Stewart - The Courtier and the Heretic Ch.10
Book Reference
Stewart,Matthew: 'The Courtier and the Heretic' [Yale 2007], p.162
A Reaction
Spinoza had a rather appealing waspish wit. This nicely dramatises an ancient idea (Idea 407). You can, of course, if you believe in God, infer some of His characteristics from His creation. But then see Hume: Ideas 1439, 6960, 6967, 1440.
Related Ideas
Idea 407 Mortals believe gods are born, and have voices and clothes just like mortals [Xenophanes]
Idea 6960 Analogy suggests that God has a very great human mind [Hume]
Idea 6967 Order may come from an irrational source as well as a rational one [Hume]