Gottfried Wilhelm Leibniz, letter to Count Ernst von Hessen-Rheinfels (Aug. 14, 1683) in Gottfried Wilhelm Leibniz: Sämtliche Schriften und Briefe (1923-) II.ii. p. 535, as translated by Matthew Stewart, The Courtier and the Heretic (2006) pp. 228-229.
Context: Regarding Spinoza, whom M. Arnauld has called the most impious and most dangerous man of this century, he was truly an Atheist, [i. e., ] he allowed absolutely no Providence dispensing rewards and punishments according to justice.... The God he puts on parade is not like ours; he has no intellect or will.... He fell well short of mastering the art of demonstration; he had only a mediocre knowledge of analysis and geometry; what he knew best was to make lenses for microscopes.