In this paper, I discuss, as carried out by Gaven Kerr, a reconstruction of Aquinas’s argument for the existence of God from his work De Ente et Essentia. My analysis leads to complementing Kerr’s proposal with the following elements: a summarization of the presented argument in a more formal manner; a specification of the main presuppositions of the Thomistic conception of existence; a drawing of attention to the fact that the essence–esse composition is a borderline case of the array of (...) potency–act compositions; a distinguishing of the empirical and speculative interpretations or versions of Aquinas’s argument; a clarification of what is the Divine exception from the essence–esse composition; a distinguishing of the three models of participation and a defence of the moderate model. I regard the following two issues to be of key importance for the argument under discussion: the relation between the Aristotelian compositional model and the Platonic model of participation as well as the defence of the Thomistic conception of the essence–esse composition. (shrink)