A genius (genius) was a semi-divine, mortal being who endows a man with fertility, directs his fate, brings happiness, and is born with him. The female counterpart is Junona (iuno).
A genius is born with a man and dies, he takes care of him and gives advice and warnings. After his death, he stays underground and looks after the deceased’s family. The genius was called “birth companion” (natnatale comes) and “the mortal god of human nature” (naturae dees humanae mortalis). Each place had its genius – genius loci. It was said that “there is no place without a genius” (nullus locus sine genio), for example, the genius of the marriage bed is lectus genialis, who watches over the fertility of the spouses.
It was believed that every man had his own individual genius. Offerings were made to him on his birthday – hence Christians initially suppressed the celebration of birthdays, as it is a pagan holiday in honour of their own genius (the Christian substitute is name day, a holiday in honour of the godfather of the patron saint). The genius was offered food and drink. The cult of genius played a special role during the empire when the genius of the ruler was honoured.
The concept of genius was supplemented over time with a collective genius, as exemplified by genius populi Romani, the guardian spirit of the entire “Roman people”, that is, all Romans. On the reverse of Roman coins, the genius was usually depicted in the form of a serpent, often with house deities, or as a naked young man or a man in a toga with a platter and a cornucopia, sometimes with an altar at his feet. Genius was a frequent motif in decorative allegorical sculpture and painting.
Under the influence of Greek philosophy, there was a later division into good genius – white (genius albus) and evil – black (genius ater). Genius was generally identified with the Greek demon (dajmon).