We are unable to determine whether the early medieval Slavs knew about the concept of the soul before the introduction of Christianity in their lands. What we do know, however, is that they must have had some beliefs concerning the Otherworld and the post-mortem existence of their dead. The first textual accounts concerning traditional Slavic beliefs about the soul are known from the High Middle Ages.
According to these beliefs the human soul was conceived as being similar to a living person. It could walk, sit, eat, drink, leave footprints or handprints, breastfeed orphans and have sexual intercourse with the living. Although the souls were invisible for the living, they occupied part of their space. Therefore, people had to be wary not to poke them, step on them or splash them with slop (Moszyński 1967: 586). Such perceptions of the human soul, which stood in glaring contrast to the official Christian eschatology, to some extent had to have resulted from pagan beliefs.
From Slavic Journeys to the Otherworld. Remarks on the Eschatology of Early Medieval Pomeranians, Kamil Kajkowski.
