IT HAS BEEN SHOWN THAT SUAREZ WAS THE WATERSHED for much of modern metaphysics understood as the science or the philosophy of being, or as ontology.(1) Not only was he the first to write a systematic treatise in metaphysics that broke with the centuries-long tradition of commenting on the Metaphysics of Aristotle, but he also set metaphysics on a new course that was to define the parameters for ontology as the modern version of the ancient science of being as being. Heidegger himself recognized this significance of Suarez for modern metaphysics, as he was beginning to work out his own reconstruction of a philosophy of being in terms of an ontological difference between be and being, when he wrote of Suarez as "putting the ontological problems into a systematic form for the first time, a form which determined a classification of metaphysics that lasted through subsequent centuries down to Hegel."(2) I would argue that Heidegger should have included himself in that classification, along with Wolff, Kant, and Hegel, even though he was trying to break out of it by positing the ontological difference as the basis for raising anew the modern question of being.
It should be pointed out that Suarez himself proceeded by way of a very elaborate deconstruction of previous metaphysics in his many Metaphysical Disputations(3) before setting down his own systematic reconstruction, much as Heidegger was to do in going over repeatedly the metaphysical tradition which he claimed had to be deconstructed. Unlike Heidegger, however, Suarez did come up with an elaborate reconstruction of his own which was to influence subsequent reconstructions such as those of Descartes and Wolff. It should also be pointed out that this reconstruction was quite different from the more ancient reconstructions going back to Aquinas, Aristotle, Plato, and even Parmenides. Heidegger did not see this difference very clearly, which resulted in his treating the metaphysical tradition as if it were all one and the same going back from Hegel to Plato. Having recognized the great divide in the tradition which Suarez represents in the history of metaphysics, however, we could say that Heidegger's deconstruction was a deconstruction of modern metaphysics or ontology and not of the more ancient science of being as being. If Heidegger had recognized this difference between ancient and modern metaphysics in his deconstruction, he might have gotten a little further than he did in his attempt at reconstructing the question of being.
At the beginning of Being and Time Heidegger laid out his own parameters for this question in terms of an ontology that had to supersede the merely ontic consideration of the particular sciences,(4) even though he did not immediately proceed to elaborate on such an ontology. He argued rather that before one can properly pursue the question of being he had in mind, one has to analyze the structure of Dasein, the particular being who raises the question of being, in order to gain a proper understanding of the being in question or, more exactly, of the be of being, das Sein des Seienden, not to be confused with the ancient metaphysical question of being as being. In other words, before one could begin a reconstruction in ontology, one had to do a reconstruction of the being doing ontology, a Daseinsanalytik. In his original project Heidegger thus had two clearly delineated parts in mind: first, a reconstruction of Dasein, which would serve as a preliminary to ontology much as Kant's Critique of Pure Reason had been supposed to serve as a preliminary for doing metaphysics, and second, a reconstruction of the question of being itself starting from the ontological difference between be and being which Heidegger already had clearly in mind. The first part was to go from being to time, and the second part was to reverse this or turn it around from time to being.
As we know, the second part of this project never came to fruition, at least not as originally promised, though there were many attempts later on to make this famous turn, none of which ever resulted in anything like a full blown reconstruction of ontology. …