"The whole effort of Thomas tended towards theology. And metaphysics is for him only a program given by some definitions of science (in the commentary on Boethius' De Trinitate above all), and by his commentary on Aristotle. But he never develops a proper metaphysics. We can say still more: he did not give metaphysics the status of a rigorous science, but only [a science] in the broad sense. A rigorous science is founded on univocal concepts. But, as Thomas stresses, being is not univocal. Metaphysics does not function except with analogous terms: it is therefore a science only in a broad, supple sense."
Géry Prouvost, “Quand commence l’ontothéologie? Aristote, Thomas d’Aquin et Duns Scot,” Revue thomiste 95 (1995): 101 (85-108).