And then, a little Jew, with a long nose and a pale complexion, Poor but satisfied, pensive and reserved, A subtle but hollow spirit, less read than celebrated, Hidden under the mantle of Descartes, his mentor, Walking with measured steps, comes close to the great being: Excuse me, he says, addressing him in a whisper, But I think, just between us, that you do not exist at all.
source
Voltaire's poem, as quoted in António Damásio's Looking for Spinoza: Joy, Sorrow, and the Feeling Brain (Orlando, FL: Harcourt, 2003)