Ontology

When it comes to questions of ontology, Chatton’s leanings are Scotistic. Indeed, his treatment of issues in ontology often consists in his defending hallmark Scotistic doctrines against criticism - usually, against objections raised by Ockham and Peter Auriol (d. 1322). For example, Chatton adopts Scotus’ views about universals as well as his theory of individuation; accordingly, Chatton labors to defend the Scotistic doctrines of common nature and haecceitas. (Chatton does not actually use the term haecceitas, however; instead, following Scotus’ own usage in the Ordinatio, he uses individualis differentias.) Again, Chatton follows Scotus - and opposes Ockham - in arguing for the reality of ten (irreducibly) distinct classes of entity corresponding to each of Aristotle’s ten categories. In this connection, he gives special attention to defending the reality of both quantity (as something distinct from substance and quality) and relation (as something distinct from absolute entities).

Although the sorts of ontological views Chatton adopts are not particularly original, his defense of such views are often subtle and innovative. One particularly notable example is his development and application of a certain meta-ontological principle to derive a number of realist metaphysical commitments. The principle, which Chatton himself refers to simply as ‘‘my rule’’ (mea regula) or ‘‘my principle’’ (mea propositio), has come to be known in the literature as “Chatton’s antirazor’’ - a label indicative of his use of it as a foil for Ockham’s famous razor. Chatton deploys the principle in a variety of contexts, and its precise formulation varies and develops across these contexts, but the following can be taken as representative: ‘‘where an affirmative proposition is made true by things (res), if fewer things (uniformly present, without anything else) cannot suffice [for that proposition’s being true], one must posit more’’ (Collatio et Prologus, 33). So stated, the principle is hardly controversial; yet the way in which Chatton elaborated and applied the principle was quite contentious.

A case in point is Chatton’s use of the anti-razor against Ockham’s reductionism about relations. In Rep. I, d.30, q.1, a.4, Chatton considers whether it should be

Allowed that there are relational accidents - that is, a distinct class of entities corresponding to the (accidental) category of relation. He argues in the affirmative, defending in particular the reality and irreducibility of causal relations. His strategy throughout is straightforward: he considers six cases of true relational statements (e. g., ‘‘Socrates generates Plato,’’ ‘‘Heat produces heat,’’ ‘‘This hand moves a stick,’’ etc.) and argues that in each case merely absolute (or non-relational) entities - regardless of the number or type invoked - ‘‘will not suffice’’ for the truth of such statements. And, as his discussion makes explicit, he thinks an entity suffices for the truth of a given statement just in case its existence necessitates the statement’s truth. Citing his ‘‘rule,’’ Chatton then concludes that ‘‘it is, therefore, necessary to posit relational accidents.’’

What is most significant about Chatton’s principle is the way in which it renders explicit a certain methodological approach to questions of ontological commitment. According to this approach, one’s ontological commitments extend to all and only those entities whose existence is required to explain the truth of a given set of truths. To be sure, there is nothing particularly novel in Chatton’s adopting this sort of ‘‘truth-maker’’ approach to matters of ontology. It is plausible to suppose such an approach was tacitly assumed by many, if not most, medieval philosophers. But because Chatton’s specific formulation of the principle underlying this approach proved controversial, his use of it also had the effect of calling attention to methodological assumptions guiding metaphysical speculation.

As we have seen, Chatton’s principle places particular emphasis on the criterion of sufficiency for truth-making, which in turn suggests that the truth-maker for a given statement can simply be identified with that entity (or those entities) whose existence necessitates its truth. So understood, however, Chatton’s principle is open to a number of objections - ones which his contemporaries were quick to raise. Thus, at QuodlibetI.5, Ockham explicitly argues against Chatton’s principle, offering a counterexample (one involving God’s creation of an angel) designed to show that an entity’s being sufficient for the truth of some statement is not necessary for making it true. Indeed, as he sees it, the truth-maker for a given statement is ‘‘sometimes sufficient to make the sentence true, but sometimes not.’’ And, some years later, Adam Wodeham (d. 1358), Chatton’s slightly junior confrere, uses roughly the same example to argue that sufficiency is not a sufficient condition on truth-making either. Even if his principle was not widely adopted as a means for identifying a statement’s truth-makers (and, hence, ontological commitment), Chatton’s principle seems to have had the effect of focusing attention on what exactly truth-making involves.