The author analyses the semantics in theological context as well as the hierarchy of science according to Thomas Aquinas. By means of the analysis of the use of suppositions, of the relation between God and creation and divine persons he shows that according to Thomas Aquinas logic is the necessary and metaphysics the sufficient condition of theology. The author argues that Thomas Aquinas is an adherent of the inherence theory of predication, nevertheless in some contexts he implicitely overcomes the latter in favour of functional theory of predication.