The study focuses on the life and ideas of Giordano Bruno, who was persecuted by the Inquisition, which sentenced him to death. The book consists of 29 chapters. The author considered Bruno's legacy anti-clerical and anti-religious, because Bruno criticized the Church as a part of the feudal system. R. analyzed Bruno's ideas not only from the point of view of opposition to ecclesiastic institutions, but also noted that the thinker's worldview had been provoked with the social conditions of a transitional epoch. R. pointed to the continuity of Bruno's ideas from Leonardo da Vinci, noting the special influence of Copernicus. According to R., when studying the works by philosophers of the Middle Ages, it is important to take into account that thinkers, in order to avoid persecution of the Inquisition, resorted to using allegorical language, so we are not entirely clear about some of the meanings in Bruno's work ‘The Expulsion of the Triumphant Beast’. One of the important ideas of Bruno, according to the author, was the assertion of the infinity of the universe and the countless number of worlds. R. pays a special attention to Bruno's relationship with Protestants, noting that he criticized not only Catholic Church, but also, for instance, Calvinists. Besides, he came up with the idea of secularization of the land belonged to monasteries and parishes and depriving all the privileges of clergy and monks.
R. emphasized the complexity of Bruno's worldview; the philosopher, on one hand, criticized the religious world order, but, on the other hand, he was a pantheist, discussing such concepts as ‘world soul’, and ‘double substance’.
Beside analyzing the ideas of Giordano Bruno, his life and conflict with the Inquisition, R. examines the issue of the impact of Bruno’s legacy on the views of other thinkers. The author shown the significance of Bruno's legacy for subsequent epochs - from Hegel to W. Wundt, and F. Lange, examined the attitude of the Church towards him, in particular, including the Pope's Message of 1888, which condemned secular education and freedom of speech, as well as the opening of the monument for Bruno in Rome, which had political significance in Italy.