Sean M. Costello (University of Michigan): Aristotle on Building the World from the Ground (and other Elements) Up: An Eduction-Driven Theory of Hylomorphic Ordinary-Object Ontology

The ancient Greeks, like metaphysicians today, were exceptionally interested in questions concerning ordinary-object ontology and the fundamental building blocks which composed such objects. In particular, they investigated the threefold intertwining topics of (1) what objects were to be admitted into their ontology, (2) what these objects had to be like metaphysically in order to be ontologically robust, and (3) if – and, if so, how – such objects were able to undergo changes and transform into one another. The purpose of this project shall be to elucidate Aristotle’s thoughts on these matters, with particular attention being paid to his positions concerning the second and third topics.

I begin this work by briefly delineating the intellectual environment amongst which Aristotle developed his own metaphysical views, pointing out his Eleatic, ontological monist, and ontological pluralist predecessors. Then, after briefly unpacking several of Aristotle’s key relevant theoretical innovations, I contend that, in answer to (1) – and due to his commitments to a modest form of empiricism, formal causation, and his tenfold categorical schema – he must hold a naïve ontology, wherein inanimate natural objects, living beings, and (though there is some controversy over this) even artifacts are considered to be ontologically robust.

I then emphasize that, due to Aristotle’s deep respect for the intellectual tradition that he inherits, his answers to (2) and (3) must be informed by overcoming two worries raised by the Presocratics – namely, (i) the Parmenidean concern about generation from, and corruption into, nothing simpliciter and (ii) the dual-pronged worry of reducing generation and corruption to alteration either by positing (a) a single substratum, as the monists do, or (b) indestructible elements, as the pluralists do. Recognizing that examining the manner in which the elemental building blocks – which, for Aristotle, are the Empedoclean four of fire, air, water, and earth – interact with one another will most-clearly reveal Aristotle’s metaphysical principles of hylomorphism, I turn to examine his theory of elemental transformation, intending to provide by an answer to (2) through discovering an answer to (3). With this in mind, I examine several of the prominent modern scholarly attempts to understand how elemental transformation occurs, testing them against the need to avoid the two Presocratic worries mentioned above. I find, however, that all of these theories fall prey to one of the two worries – with the positions put forth by Zeller (1897), Furth (1988), Gill (1989), and Charles (2004) all violating the first concern and Lewis’s (2008) theory violating the second.

With the logical space cleared, I then present an alternative explanation of Aristotle’s answer to (3), wherein elemental transformation occurs according to certain essential, second-potentiality ‘eduction conditions’ (conditions, grounded in the currently-existing hylomorphic element itself and expressed in its account, for a new element to be substantially educed from the currently-existing element), and is kept track of by a ‘hylomorphic history property’ (a property of the newly transformed element explaining that it was ‘actually educed from’ the previous element). I suggest that such a position is able to avoid both Presocratic worries and then explain how this means that, on Aristotle’s view – in answer to (2) – the hylomorphic substance should be treated as ontologically basic, possessing the inextricably linked logical principles of matter as potentiality and form as actuality as aspects of its essence. I then briefly conclude by demonstrating how this theory can account for both horizontal substantial change (i.e. between elements) and vertical substantial change (i.e. between elements and more complex objects).


This lecture was given on Thu, 1 July 2021, 13:00 (UK time) as part of the workshop Change and Changemakers in Ancient Philosophy. The workshop is a collaborative initiative of the Change and Changemakers Network (Siegen) together with the Mereology of Potentiality Project (Oxford).