Book M. P. Ivanovsky is devoted to the almost two-century struggle of advanced space scientists for the triumph of the idea of the development of the part of the Universe surrounding us. It, along with firmly established facts and well-developed theories, sets forth a number of hypotheses, many of which are now only bold guesses. Without these hypotheses, the further development of cosmogony is unthinkable. Some of them will eventually turn into theories, while others will be refuted by the further development of science. But all of them will play a role in solving the great task of studying the development of the stellar world. Among popular science books on astronomy book M. P. Ivanovsky is not only the first in Soviet literature, fully devoted to the problems of cosmogony, but also the only book that outlines the current state of this science.