In the project “Metaphysical Themes in Croatian Renaissance Aristotelians” (MeTopCro) we will investigate the contributions of Croatian Aristotelians to debates that are representative of Renaissance philosophy as a whole. Specifically, (1) we will study and provide a comprehensive assessment of Nikola Vitov Gučetić’s conception of the immortality of the soul, a quintessential problem of Renaissance philosophy. (2) We will deepen our understanding of Gučetić’s output through focused research of archival materials. (3) We will examine and evaluate Juraj Dubrovčanin’s rational critique of astrology from the perspective of astronomy as a mathematical science. (4) We will analyze Matija Frkić’s bold innovations in metaphysics, particularly in cosmology, where he abandoned the Aristotelian fifth element as the substance of celestial bodies, as well as Frkić’s innovative interpretation of the ancient axiom that “nothing comes from nothing,” which had to be reconciled with the teachings of the Book of Genesis. These four research directions will contribute to a well-founded assessment of the originality and contribution of Croatian Renaissance Aristotelianism to European philosophy and science.