Abstract

The paper analyses Averroes's and Aquinas's different reconstructions of Aristotle's ontology in the central books of the Metaphysics. The main claim the paper argues for is that Averroes endorses an explanatory criterion of substantiality, while Aquinas favours an independent existence criterion. The result of these different choices is that the Arabic commentator believes that the forms of sensible objects are more substances than the objects of which they are the forms, while the Dominican Master sticks to the traditional picture that sensible objects hold some kind of priority over their ontological constituents in general and over form in particular. For Averroes, therefore, the central books of the Metaphysics mark a major departure from the Categories ontology, where particular sensible objects are regarded as fundamental entities and so primary substances. On Aquinas's reconstruction, by contrast, sensible objects are still thought of in the Metaphysics as primary substances in spite of their being analysable into matter and form