The Ground of the Universal in the Singular According to Thomas Aquinas: Common Nature, Similitude, and/or Idea?

In this article, I aim to analyze in Thomas Aquinas’s philosophy (i) if the “absolutely considered essence” (or “common nature”) can play a role of basis or ground of the universal in the singular thing or individual and (ii) if it is simultaneously obtained with the intelligible abstraction of the essence that joins the intention of universality or by a “double abstraction”. Additionally, I will try to consider if the “absolutely considered essence” requires or not from Aquinas an appropriation of certain theory of ideas, and whether the association between this essence and ideas is something required to justify the “similitude” among the universals and the individuals. Finally, I will recall some different receptions of Thomas Aquinas in the 20th and 21st centuries, most of them used to frame his thought under so distinct basis such as direct realism, essentialism, indirect realism, representationalism etc.