The work of Thomas Aquinas (circa 1225-1275) is extensive, and its form is alien in relation to the texts of ancient and modern philosophy, often appearing off-putting in some respects. The historical circumstances of its creation are known only in incomplete details, which are overwhelming in number. With this introduction, Rolf Schönberger provides an initial access to the writings of the most significant theologian and philosopher of the Middle Ages, who combined the inherited Augustinianism with the teachings of Aristotle, and was therefore attacked by both the Augustinian-influenced school tradition and Aristotelianism.