Zusammenfassung / Summary
What is Aristotelian metaphysics? The “first philosophy” asks for the unity of the various meanings of ‘being’. The semantic question is a question for the causal dependences of being. The ontological analysis of the perceptual, changeable ousia is anti-reductionistic and anti-deterministic. (a) The ontological concepts apt for the description of parts are not sufficient to grasp the whole. (b) The processes in the cosmos do not constitute a single, closed causal nexus; the activity of each ousia is determined by its specific form. The Aristotelian ontology is a framework in which the human being can understand itself as an agent. Aristotelian metaphysics as theologia naturalis poses the question: How can it be explained that that which can and can not be really is? If the necessarily being would not exist, then nothing would exist. This argument does neither rest on particular cosmological premises nor does it require epistemological presuppositions, it just consists in modal-ontological reasoning.