Maureen Donnelly

Various philosophers have raised compelling objections to the standard assumption that relations hold of their relata _in a particular order_. Positionalism is an alternative to the standard account, according to which the distinction between the claims made in ‘Abelard loves Eloise’ and ‘Eloise loves Abelard’ is explained by differences in the _positions_ attributed to the relata. The former claim posits Abelard in the position of _lover a_nd Eloise in the position of _beloved_. The latter claim reverses this assignment. This chapter proposes a revised version of positionalism, _Relative Positionalism,_ based on a broadly Aristotelian notion of _relatives_. It is argued that Relative Positionalism can overcome common objections to positionalism and, unlike rival accounts, has the right structure to explain differences in the symmetry properties of arbitrarily complex relations.

In recent years, various metaphysicians have made use of qualifications that may apply to different entities relative to different individuals in accounts of such phenomena as color, secondary qualities, subjectivity, and relations. The primary purpose of this paper is to propose a further use for relative qualifications in an account of situations, where situations here are understood as engaged orientations toward the world. My central claim is that situations are distinguished from one another through the ways in which entities are qualified differently relative to different individuals. Thus, to imagine another person’s situation is to imagine entities as qualified differently—as they are for the other rather than for oneself–and need not involve directly imagining anything about that person. I show how situations involving multiple individuals may be derived from individual situations by suppressing conflicting qualifications. The resulting joint situations retain more or less of the action-guiding structure of individual situations depending on the similarity or diversity of the individuals involved.

This paper provides an axiomatic formalization of a theory of foundational relations between three categories of entities: individuals, universals, and collections. We deal with a variety of relations between entities in these categories, including the is-a relation among universals and the part-of relation among individuals as well as cross-category relations such as instance-of, member-of, and partition-of. We show that an adequate understanding of the formal properties of such relations – in particular their behavior with respect to time – is critical for formal ontology. We provide examples to support this thesis from the domain of biomedicine.

This paper presents an axiomatic formalization of a theory of top-level relations between three categories of entities: individuals, universals, and collections. We deal with a variety of relations between entities in these categories, including the sub-universal relation among universals and the parthood relation among individuals, as well as cross-categorial relations such as instantiation and membership. We show that an adequate understanding of the formal properties of such relations – in particular their behavior with respect to time – is critical for geographic information processing. The axiomatic theory is developed using Isabelle, a computational system for implementing logical formalisms. All proofs are computer verified and the computational representation of the theory is available online.

Non-symmetric relations like loves or between can apply to the same relata in non-equivalent ways. For example, loves may apply to Abelard and Eloise either by Abelard’s loving Eloise or by Eloise’s loving Abelard. On the standard account of relations, different applications of a relation to fixed relata are distinguished by the direction in which the relation applies to the relata. But neither Directionalism nor its most popular rival, Positionalism, offer accounts of differential application that generalize to relations of arbitrary symmetry structure. Here, I develop an alternative account, Relative Positionalism, which distinguishes different applications of a relation to fixed relata in terms of the ways in which the relata are characterized relative to one another. In presenting and defending Relative Positionalism, this paper covers some of the same ground as my [2016], but avoids the latter’s algebraic approach and focuses on interpretative issues—in particular, how to make sense of relative property instantiation—that were not addressed in the earlier paper.

In fields such as medicine, geography, and mechanics, spatial reasoning involves reasoning about entities that may coincide without overlapping. Some examples are: cavities and invading particles, passageways and valves, geographic regions and tropical storms. The purpose of this paper is to develop a formal theory of spatial relations for domains that include coincident entities. The core of the theory is a clear distinction between mereotopological relations, such as parthood and connection, and relative location relations, such as coincidence. To guide the development of the formal theory, I construct mathematical models in which nontrivial relative location relations are defined.

In this paper, I focus on three issues intertwined in current debates between endurantists and perdurantists—(i) the dimension of persisting objects, (ii) whether persisting objects have timeless, or only time-relative, parts, and (iii) whether persisting objects have proper temporal parts. I argue that one standard endurantist position on the first issue is compatible with standard perdurantist positions on parthood and temporal parts. I further argue that different accounts of persistence depend on the claims about objects' dimensions and not on the auxiliary claims about parthood and temporal parts.

Newton distinguishes between absolute and relative places. Both types of places endure through time and may be occupied by various objects at various times. But unlike absolute places, each relative place stands in fixed spatial relations with one or more reference objects. Relative places with independent reference objects (e.g., a ship and the earth) may move relative to one another. Relative places, not absolute places, are used to locate objects and track their movements in common-sense reasoning and in disciplines such as biology, engineering, and geology. The purpose of this paper is to develop a formal theory for reasoning about relative places and their changing relations to both other places and to material objects.

The theory of granular partitions is designed to capture in a formal framework important aspects of the selective character of common-sense views of reality. It comprehends not merely the ways in which we can view reality by conceiving its objects as gathered together not merely into sets, but also into wholes of various kinds, partitioned into parts at various levels of granularity. We here represent granular partitions as triples consisting of a rooted tree structure as first component, a domain satisfying the axioms of Extensional Mereology as second component, and a mapping (called ’projection’) of the first into the second as a third component. We define ordering relations among granular partitions the resulting structures are called partition frames. We then introduce an axiomatic theory which sentences are interpreted in partition frames.

Mereological principles are sometimes used to support general claims about the structure and arrangement of objects in the world. I focus initially on one such mereological principle, the weak supplementation principle (WSP). It is not obvious that (WSP) is prescribed by ordinary thinking about parthood. Further, (WSP) is not needed for a fairly strong formal characterization of the part–whole relation. For these reasons, some arguments relying on (WSP) might be countered by simply denying (WSP). I argue more generally that there is no reason to assume that one core mereology functions as a common basis for all plausible metaphysical theories.

It is often assumed that indeterminacy in mereological relations—in particular, indeterminacy in which collections of objects have fusions—leads immediately to indeterminacy in what objects there are in the world. This assumption is generally taken as a reason for rejecting mereological vagueness. The purpose of this paper is to examine the link between mereological vagueness and existential vagueness. I hope to show that the connection between the two forms of vagueness is not nearly so clear-cut as has been supposed.

Standard theories in mereotopology focus on relations of parthood and connection among spatial or spatio-temporal regions. Objects or processes which might be located in such regions are not normally directly treated in such theories. At best, they are simulated via appeal to distributions of attributes across the regions occupied or by functions from times to regions. The present paper offers a richer framework, in which it is possible to represent directly the relations between entities of various types at different levels, including both objects and the regions they occupy. What results is a layered mereotopology, a theory which can handle multiple layers (analogous to the layers of a lasagna) of spatially or spatiotemporally coincident but mereologically non-overlapping entities.

We propose an ontological theory that is powerful enough to describe both complex spatio-temporal processes and the enduring entities that participate therein. For this purpose we introduce the notion a directly depicting ontology. Directly depicting ontologies are based on relatively simple languages and fall into two major categories: ontologies of type SPAN and ontologies of type SNAP. These represent two complementary perspectives on reality and employ distinct though compatible systems of categories. A SNAP (snapshot) ontology comprehends enduring entities such as organisms, geographic features, or qualities as they exist at some given moment of time. A SPAN ontology comprehends perduring entities such as processes and their parts and aggregates as they unfold themselves through some temporal interval. We give an axiomatic account of the theory of directly depicting ontologies and of the core parts of the metaontological fragment within which they are embedded.