Compositionalists hold that God the Son became human by acquiring all the parts that ordinarily compose a human being (his ‘human nature’). To be orthodox, though, they must deny that Christ's human nature is a person, even though it has all the parts that human persons ordinarily have. One way to do this is by appealing to the principle that no member of a natural kind can have another member of the same kind as a proper part. Since Christ is a person, he cannot have another person as a part, so if his human nature is a part of him, it cannot be a person. This principle is defended on the grounds that it can resolve metaphysical problems involving apparently multiple individuals of the same natural kind that share the same space. I argue that this is a weak strategy. First, it leaves unanswered key questions about how and why the principle applies to the incarnation. Second, counter-examples to the principle exist, suggesting that it is not true. Third, there is a better solution to the kinds of metaphysical paradoxes for which this principle is usually invoked, but this solution cannot be applied to the case of Christ. Consequently, compositionalists should not rely on this principle as a means of avoiding Nestorianism.

In this paper, using a propositional modal language extended with the window modality, we capture the first-order properties of various mereological theories. In this setting, $\Box \varphi $ reads all the parts (of the current object) are $\varphi $, interpreted on the models with a whole-part binary relation under various constraints. We show that all the usual mereological theories can be captured by modal formulas in our language via frame correspondence. We also correct a mistake in the existing completeness proof for a basic system of mereology by providing a new construction of the canonical model.

Many say that ontological disputes are defective because they are unimportant or without substance. In this paper, we defend ontological disputes from the charge, with a special focus on disputes over the existence of composite objects. Disputes over the existence of composite objects, we argue, have a number of substantive implications across a variety of topics in metaphysics, science, philosophical theology, philosophy of mind, and ethics. Since the disputes over the existence of composite objects have these substantive implications, they are themselves substantive.

This critical notice describes some of Thomas Sattig’s book The Double Lives of Objects: An Essay in the Metaphysics of the Ordinary World and raises several critical issues about it.

In this paper, I criticize Structured Propositionalism, the most widely held theory of the nature of propositions according to which they are structured entities with constituents. I argue that the proponents of Structured Propositionalism have paid insufficient attention to the metaphysical presuppositions of the view – most egregiously, to the notion of propositional constituency. This is somewhat ironic, since the friends of structured propositions tend to argue as if the appeal to constituency gives their view a dialectical advantage. I criticize four different approaches to providing a metaphysics of propositional constituency: set-theoretic, mereological, hylomorphic, and structure-making. Finally, I consider the option of taking constituency in a deflationary, metaphysically ‘lightweight’ sense. I argue that, though invoking constituency in a lightweight sense may be useful for avoiding the ontological problems that plague the ‘heavyweight’ conception, it no longer proffers a dialectical advantage to Structured Propositionalism.

An exact truthmaker for A is a state which, as well as guaranteeing A’s truth, is wholly relevant to it. States with parts irrelevant to whether A is true do not count as exact truthmakers for A. Giving semantics in this way produces a very unusual consequence relation, on which conjunctions do not entail their conjuncts. This feature makes the resulting logic highly unusual. In this paper, we set out formal semantics for exact truthmaking and characterise the resulting notion of entailment, showing that it is compact and decidable. We then investigate the effect of various restrictions on the semantics. We also formulate a sequent-style proof system for exact entailment and give soundness and completeness results.

We present a new axiomatization of classical mereology in which the three components of the theory—ordering, composition, and decomposition principles—are neatly separated. The equivalence of our axiom system with other, more familiar systems is established by purely deductive methods, along with additional results on the relative strengths of the composition and decomposition axioms of each system.

In this paper we develop a point-free system of geometry based on the notions of region, parthood, and ovality, the last one being a region-based counterpart of the notion of convex set. In order to show that the system we propose is sufficient to reconstruct an affine geometry we make use of a theory of a Polish mathematician Aleksander Śniatycki from [15], in which the concept of half-plane is assumed as basic.

This paper introduces a framework for thinking about ontological questions—in particular, the Special Composition Question—and shows how the framework might help support something like an account of restricted composition. The framework takes the form of an account of natural objects, in analogy with David Lewis's account of natural properties. Objects, like properties, come in various metaphysical grades, from the fundamental, fully objective, perfectly natural objects to the nomologically otiose, maximally gerrymandered, perfectly non-natural objects. The perfectly natural objects, I argue, are the mereological simples, and (roughly) a collection composes an object of degree-n naturalness if and only if its members are arranged F-wise, for some property F that appears in the degree-n natural laws. Arbitrary composites turn out to be perfectly non-natural objects and are metaphysical bystanders. Ordinary composite objects fall in between. Some—e.g., atoms—are very (though not perfectly) natural; others—e.g., tables—are highly non-natural.