Citizen of the universe. Konstantin Tsiolkovsky’s cosmic philosophy and science fiction

The paper discusses Konstantin Tsiolkovsky’s philosophy as it can be reconstructed from his writings of two kinds, the academic papers and the works generally, though not always correctly, classified as science fiction. It is stressed that Tsiolkovsky belongs to the large school of Russian philosophers known as the Cosmists, and he is placed within the group of 20th century academic-minded Cosmists. The first part of the paper reconstructs Tsiolkovsky’s cosmic philosophy on the basis of his philosophical works, which amount to half of his published works. The second part of the paper discusses all the works by Tsiolkovsky available in English under the science fiction label. The paper also contains comparisons of Tsiolkovsky’s views with the philosophicalreligious system propagated by Nicholas and Helena Roerich, known as Agni Yoga, and its ancient Indian roots. It is also mentioned that Tsiolkovsky played an important role in the development of the early Russian, or more properly Soviet, science fiction movies. The paper stresses that Tsiolkovsky always based his writings on solid scientific foundations, so that the label “science fiction” does not always apply to them.