Men have been so mad as to believe that God is pleased by harmony. - Benedictus de Spinoza

Neophil: ...Leibniz, Wolff, and their various successors, to what a level of perfection and completeness they have brought philosophy! How proud Germany can be of them! Yet what does it help to claim more for oneself than is right? Let us always acknowledge that someone other than a German, I add further, someone other than a Christian, namely, Spinoza, has participated immensely in the work of bettering philosophy. Before the transition from the Cartesian to the Leibnizian philosophy could occur, it was necessary for someone to take the plunge into the monstrous abyss lying between them. This unhappy lot fell to Spinoza. How his fate is to be pitied! He was a sacrifice for the human intellect, but one that deserves to be decorated with flowers. Without him, philosophy would never have been able to extend its borders so far.

[Spinoza] — A God-intoxicated man. [Original in German: Ein Gottbetrunkener Mensch.]

While Herr Bernstein returns to Kant “to a certain point” Herr Stern speaks to us of the old Spinoza, and asks us to return to the philosophy of that great and noble Jewish thinker. That is something else, and far more reasonable than Herr Bernstein's call. Indeed, it is important and interesting to study the question of whether there is something in common between the philosophical ideas of Marx and Engels on the one hand, and Spinoza's on the other. [...] Meanwhile, I assert with full conviction that, in the materialist period of their development, Marx and Engels never abandoned Spinoza's point of view. That conviction, incidentally, is based on Engels's personal testimony. [...] After visiting the Paris World Exhibition in 1889, I went to London to make Engels's acquaintance. For almost a whole week, I had the pleasure of having long talks with him on a variety of practical and theoretical subjects. When, on one occasion, we were discussing philosophy, Engels sharply condemned what Stern had most inaccurately called “naturphilosophische materialism”. “So do you think,” I asked, “old Spinoza was right when he said that thought and extent are nothing but two attributes of one and the same substance?” “Of course,” Engels replied, “old Spinoza was quite right.”