The book of the outstanding historian of philosophy M. Grabmann introduces into the problems the "Sum of Theology" by Thomas Aquinas, the most significant work of the European Middle Ages. The author reveals the historical context in which Summa was created, refers to the works of Aquinatus's predecessors, contemporaries and commentators, citing a colossal array of historical material; in addition, the enduring significance of this work for Catholic theological thought is especially explored.