In an article published in 1930, Lev Vygotsky refers explicitly to the seventeenth century Dutch philosopher Benedictus de Spinoza. From a close reading of Vygotsky’s remarkable piece, ‘The socialist transformation of man,’ the extraordinary parallels in the lives and philosophies of Vygotsky and Spinoza are revealed. Then the strengths and weaknesses are assessed of the analytical approach Vygotsky may have inherited from Spinoza. It is suggested that there are analytical ramifications arising from Vygotsky’s possible reliance on Spinoza’s nuanced but essentially (...) dualistic philosophy. The conclusion is that the key limitation of this methodology is the elision of radical doubting with radical unknowability. (shrink)