Gianluigi Segalerba's talk "Elements of Aristotle's Ontology" on June 18th at 14:15

On Monday June 18th Gianluigi Segalerba will give a talk entitled "Elements of Aristotle's Ontology". The talk will be in Jakobi 2, 336 at 14.15.

Abstract of the talk:
In my analysis I deal with the different levels of existence proper to some entities constituting Aristotle’s ontology. I concentrate my attention on Aristotleʼs procedure of differentiation between individual (or: numerically one) entities, on the one hand, and universal (or: not numerically one) entities, on the other hand: Aristotle distinguishes in many passages of his works (for instance, in Categories 5, 3b10-21, in Metaphysics Zeta 8, 1033b19-1034a8 and in Metaphysics Zeta 13, 1038b34-1039a3) entities being (having the status of) a “this something” or a “this such” from entities being (having the ontological status of) a “quality” or being (having the ontological status of) a “such”. These somethings / These suches”, on the one hand, and “Qualities” and “Suches”, on the other hand, constitute realms of reality which cannot be confused with each other: These kinds of entities belong to realms of reality that are mutually incompatible; the realms of reality consists in individual entities, on the one hand, and in universal properties, on the other hand.

Individual entities are instances of properties (or: instantiated properties); universal properties are programmes/dispositions instantiated by individual entities. The particular field of the instances is always constituted by individuals (by individual entities), while the whole field of existence is constituted both by individuals (by individual entities) and by universal properties (universals are deputies for properties).

Properties, at least biological properties like “being man” or “being animal”, are programmes/dispositions being concretized through their instances; their existence does not depend on the existence of one instance, but it does depend, however, on the existence of the whole instances; that is, there are no not-instanced properties in Aristotle (a universal property, in order to exist, must have at least an instance; otherwise it does not exist). I take some suggestions from Aristotle's defence of the principle of contradiction in Metaphysics Gamma in order to show the value of the principle of contradiction as the structural formula of reality and likewise in order to show the relationships between principle of contradiction and properties: I plead for the presence of an ontological defence strategy of the principle of contradiction besides the logical defence strategy. In order to explain the consequences deriving from a confusion between realms of reality, I take into consideration the arguments of “the One over Many” and of the “Third Man” from Aristotleʼs lost work “De Ideis”.

Finally, I take into examination Lowe's ontological square and the interpretation of the entities connected to Lowe's ontological square, since I am convinced that Lowe's proposal of the ontological square and Lowè’s conception of dispositions and of occurrences represent very valuable instruments in order to understand Aristotle's ontology; in spite of my fundamentally agreeing with Lowe I propose, however, some modifications in relation to Lowe's interpretation of the entities constituting the ontological square