The work of Julius Firmicus Maternus, a Latin writer and astrologer of the 4th century, “The Teaching in 8 Books” (“Mathesіs libri VIII”), begun during the life of Constantine the Great, completed in 354, is the most detailed textbook on the astrological science of the ancients. Of the 8 books of the work, written under the influence of Neoplatonism, the most general data is contained in the 2nd book; The 1st presents examples from Roman history, the rest are of a special nature. The sources of Firmicus Maternus are as amazing as the treatise itself; for example, the author refers to the writings of Abraham and Aesculapius. Firmicus Maternus has the highest opinion of the science he expounds. According to him, astrology uplifts and purifies the soul; whoever devotes himself to its study should feel pure and holy. Also very curious is the author’s desire to protect astrology from the persecution of higher power, with the statement that the emperor alone is not influenced by the stars. The last complete edition of the treatise dates back to 1551.