The work is dedicated to the Italian thinker Julio Cesare Vanini (1585-1619). Vanini’s biography is given in the broad context of the Italian and European history of the sixteenth – seventeenth centuries. The author covers the main philosophical currents of this period, as well as the ideological struggle around the teachings of Vanini. Catholic Church, in general, and the Inquisition, in particular, are characterized as opponents to science and the freedom of thought. For the author, Vanini is, first and foremost, an advanced philosopher. The emphasis is on his criticism of religion and Church; R. supposes that orthodox Catholic ideas in the treatises by Vanini were only a disguise for his radical thoughts. However, the researcher notes that such eclecticism was quite typical for the time when many authors also did not have a strict system of beliefs. According to R., the ideas of Vanini belonged to the transitional character of the era, which was characterized with the destruction of the feudal order and the first bourgeois revolutions. One of the key ideas by Vanini, there was a refutation of an idealistic ecclesiastic theory of the creation of the world, the place of which was replaced by the doctrine of eternity and the incompatibility of matter. The author also points out that despite Vanini’s lack of development of the theory of knowledge, his writings still provided an answer to the question about the relation of thinking to being. The author analyzed in detail Vanini’s views and came to a conclusion that those ideas combined atheism with pantheism and materialism.