The purpose of the article is to discuss the main thesis of Lev Semënovi Vygotsky’s Emotions Theory, written between 1931 and 1933 and left unfinished by the author. In his analyse of the relationship between cognitive faculty and affections, Vigotsky propose a pattern far from the dualist reductionism which condemn psychology to a choice between body and mind. He considers necessary to overcome the Cartesian paradigm of the early XX century theories of emotions, thanks to a recovery of the monistic perspective elaborated by Spinoza. Vigotsky strives to understand the dialectic between biological and cultural factors in the constitution of emotions to conceive them in terms of transformation and development.