The author describes the current state of studying of the biography and works of Pierre Pascal, the well-known French intellectual who participated in the Russian revolution of 1917 and then became one of patriarchs of the French Slavic philology. This personality appears to be especially claimed by philologists and historians. Pascal really has lived «two lives»: being the communist and the Marxist, it has spent 17 years in the USSR, and subsequently, being disappointed in revolutionary ideals, has returned home and became the prominent expert in history of Russian religious schism.