Substance ontologies in the Aristotelian tradition are commonly thought of as being constituent ontologies, because they typically espouse the hylemorphic dualism of Aristotle's Metaphysics, a doctrine according to which an individual substance is always a combination of matter and form. A common presumption is that ontologies inspired by Aristotle are 'constituent' ontologies, whereas ones inspired by Plato are 'relational', a presumption founded on the notion that Aristotle's metaphysics is distinctively 'immanent' whereas Plato's is distinctively 'transcendent'. Hylemorphism certainly has many attractive features, and many advantages over the transcendent view. Aristotle articulates four-category ontology such as hylemorphic ontology, constituent ontology, relational ontology and transcendent ontology. The author concludes that the four-category ontology, properly understood, has to be excluded both from the class of relational ontologies and from that of constituent ontologies.