In the sixth century, a series of natural disasters struck the Eastern Roman Empire, the most serious of which was the plague that raged from 541 to 542. The contemporary consensus is that Justinian's reign brought a fundamental cultural transformation and, according to Misha Meier's (2016) research, the plague marked a significant caesura in the transition from late antiquity to the Byzantine Middle Ages. The article is based on the assumption that the catastrophic events were a trigger for the transformation of the therapeutic piety, the development of which was conditioned by the ability to project the unreal. The purpose of the paper was to analyse counterfactual projections in rituals created as a response to the disasters besetting in the age of the Emperor Justinian. The author proposes to treat these religious formulas as visualised forms of counterfactual thinking based on the integration of cause and effect, according to the theory of conceptual blending. The article concludes that in case of the 6th century, counterfactual thinking enabled the transformation and development of early mediaeval culture and may have reduced the stress associated with the catastrophic events that affected the society of the Byzantine Empire.