Spinoza founds Modern materialism in its highest form, determining the horizons of both Modern and contemporary philosophical speculation within an i… - Benedictus de Spinoza

Kant is erroneously viewed as the founder of German philosophy, and an ingenious poet-philosopher, Heinrich Heine, has even drawn a parallel between the different phases of the French Revolution and those of German philosophy, putting next to each other as analogous phenomena Kant and Robespierre, Fichte and Napoleon, Schelling and the Restoration, Hegel and the July Revolution. But the true founder of German philosophy - if one wishes to name a personal representative for the spirit of the age [Zeitgeist] - is none other than [the thinker] whose world view lies equally at the foundation of French social philosophy - Spinoza; and as far as Heine's analogy goes, it is only Kant and Robespierre, i.e. the religious revolution, who are analogous phenomena.

You compare Cardozo with Spinoza; but as far as I can judge by your book there is no intellectual comparison. Spinoza was not soft. I have been all my life long a fervent disciple of Spinoza precisely on account of his firmness, of his uncompromising naturalism. Yet even he leaves out the three traditions which, however false their cosmology, seem to me morally sound: the Greek, the Catholic, and the Indian. I am therefore not a disciple of Spinoza in his ideal of human life: It leaves out poetry, art, traditional religion, military and constructive patriotism. His society would be a tame society, where there would be no masters, but all would be voluntary slaves. Perhaps you feel something of my difficulty when you point out that "art" is an indispensable ingredient in everything human.

I believe we can guess at the first time Einstein read Baruch Spinoza's Ethics (Ethica Ordinae Geometrico Demonstrata), a system constructed on the Euclidean model of deductions from propositions. Soon after getting his first real job at the patent office, Einstein joined with two friends to form a discussion circle, meeting once or twice a week in what they called, with gallows humor, the Akademie Olympia. We know the list of books they read and discussed. High among them, reportedly at Einstein's suggestion, was Spinoza's Ethics, which he read afterwards several times more. Even when his sister Maja joined him in Princeton in later life and was confined to bed by an illness, he thought that reading a good book to her would help, and chose Spinoza's Ethics for that purpose. By that time Spinoza's work and life had long been important to Einstein. He had written an introduction to a biography of Spinoza (by his son-in-law, Rudolf Kayser, 1946); he had contributed to the Spinoza Dictionary (1951); he had referred to Spinoza in many of his letters; and he even had composed a poem in Spinoza's honor. He admired Spinoza for his independence of mind, his deterministic philosophical outlook, his skepticism about organized religion and orthodoxy – which had resulted in his excommunication from his synagogue in 1656 – and even for his ascetic preference, which compelled him to remain in poverty and solitude to live in a sort of spiritual ecstasy, instead of accepting a professorship at the University of Heidelberg.