The ideas of Konstantin Tsiolkovskii, the world’s first rocket inventor, offered a whole host of opportunities to Russian writers and artists who, at the beginning of the 20th century, were seeking a new world view to broaden their sources of artistic and ideological inspirations. However, his views as a philosopher and thinker received little attention, despite the fact that he was decorated with the Soviet State Medal of Honor in recognition of his brilliant achievements as a scientist. This paper examins Tsiolkovskii’s thoughts on science and philosophy together with his influence on contemporary Soviet intellectuals, especially those who have been less studied so far rather than those who have already been explored in association with Tsiolkovskii in the context of Soviet fantasy literature. Tsiolkovskii’s scientific theories and ideas are discussed in relation to contemporary literature in three categories: confidence in evolution and world transformation by overcoming the law of entropy; conviction of human immortality based on pantheism and animism; and the manifestation of spiritual evolution in theosophy.