No reason compels me to maintain that the body does not die unless it is changed into a corpse. And, indeed, experience seems to urge a different con… - Benedictus de Spinoza

Vygotsky studied the classical German philosophy on a professional level. In his student years began his acquaintance with the philosophy of Marxism, which he studied mainly using illegal editions. At this time was born Vygotsky's interest in the philosophy of Spinoza, who would remain his favorite thinker for the rest of his life.

The first thinker to introduce the purely monistic conception of substance into science and appreciate its profound importance was the great philosopher Baruch Spinoza; his chief work appeared shortly before his death in 1677, just one hundred years before Lavoisier gave empirical proof of the constancy of matter by means of the chemist's principle instrument, the balance. In his stately pantheistic system the notion of the world (the universe, or the cosmos) is identical with the all-pervading notion of God; it is at one and the same time the purest and most rational monism and the clearest and most abstract monotheism. This universal substance, this “divine nature of the world,” shows us two different aspects of its being, or two fundamental attributes — matter (indefinitely extended substance) and spirit (the all-embracing energy of thought). All the changes which have since come over the idea of substance are reduced, on a logical analysis, to this supreme thought of Spinoza's; with Goethe I take it to be the loftiest, profoundest, and truest thought of all ages. [Original in German: Der erste Denker, der den reinen monistischen »Substanzbegriff« in die Wissenschaft einführte und seine fundamentale Bedeutung erkannte, war der große Philosoph Baruch Spinoza; sein Hauptwerk erschien kurz nach seinem frühzeitigen Tode, 1677,...]

That I might investigate the subject matter of this science with the same freedom of spirit we generally use in mathematics, I have labored carefully not to mock, lament, or execrate human actions, but to understand them; and to this end I have looked upon passions such as love, hatred, anger, envy, ambition, pity, and other perturbations of the mind, not in the light of vices of human nature, but as properties just as pertinent to it as are heat, cold, storm, thunder, and the like to the nature of the atmosphere.