Abstract

This paper critically examines five key theoretical errors in Thomas Aquinas' philosophy, particularly in his quinque viae (five ways) from the Summa Theologiae. The analysis begins with a discussion on translation issues regarding Aquinas' terminology, emphasizing the distinction between esse (being) and existence. The identified errors include: (1) the conflation of esse and essentia in God, leading to an incoherent notion of divine nature; (2) the contradiction arising from treating essence as distinct from being, rendering essence as "nothing"; (3) the presupposition of a dimension beyond God's being, undermining His ultimate condition; (4) the misidentification of God with the supreme being (maxime ens) in the quinque viae, rather than as ipsum esse subsistens; and (5) the failure of the five ways to truly demonstrate the "Being of God" rather than a mere supreme entity. The study also critiques Aquinas’ use of actus purus (pure act) and causality, suggesting that these categories improperly constrain the concept of God. Ultimately, it argues that Aquinas partially reaches an understanding of Being but remains entangled in outdated Scholastic frameworks, leading to conceptual and methodological inconsistencies.