Theories of causality obtained great development during Medieval time. Aristotelian texts had been assimilated and debated by Medieval thinkers. Causal relations became obvious not only for perceived objects that have form and matter but also for unperceived, invisible objects responsible for human behavior such as Will, Intellect, Morality and Knowledge. Many of the discussions were proficient and became fundamental for further development of such sciences as psychology, ethics, ontology etc.