The article attempts to delineate the core of the metaphysical thought of Thomas Aquinas consisting in overcoming Platonism and Aristotelianism. By following the teaching of great European Thomists of the 20th century, Etienne Gilson and Cornelio Fabro, the author tries to summarize that which, according to him, seems to constitute the core content of Thomistic metaphysics, especially its turn to the theme of being. He also refers to selected critical texts of more recent Anglo-Saxon Thomists, such as Lawrence Dewan and (...) Stephen Brock, who call for more attention to the subject of essence. By doing so, the author considers the notion of being consisted of essence and existence, the questions of ontological difference and real distinction, the relationship between the finite and the infinite, and also the linkage between causality and participation. (shrink)