Abstract
A recent study by P.R. Blum suggests the hypothesis of an ideal line from Scotus to Mastri, passing through Perera, which would tend towards a new concept of metaphysics attainable through the use of abstraction by indifference. This essay intends to test this hypothesis starting from the way in which Perera questions the unity of metaphysical abstraction through a series of innovative interpretations that are widely received in both Catholic and Reformed and Protestant domains. A first interpretation, less radical, advances a model of metaphysical abstraction, taken up by Mastri and Micraelius, which maintains the unity of metaphysics; a second interpretation, more radical, breaks the methodological unity of metaphysics through a clear distinction between ‘real’ abstraction from matter (secundum rem et rationem) and ‘mental’ abstraction by indifference (secundum rationem tantum) and, consequently, between metaphysics and ontology.