This volume tackles the slippery subject of 'meaning'.

Persistence through time is like extension through space. A road has spatial parts in the subregions of the region of space it occupies; likewise, an object that exists in time has temporal parts in the various subregions of the total region of time it occupies. This view — known variously as four dimensionalism, the doctrine of temporal parts, and the theory that objects “perdure” — is opposed to “three dimensionalism”, the doctrine that things “endure”, or are “wholly present”.1 I will (...) attempt to resolve this dispute in favor of four dimensionalism by means of a novel argument based on considerations of vagueness. But before argument in this area can be productive, I believe we must become much clearer than is customary about exactly what the dispute is, for the usual ways of formulating the dispute are flawed, especially where three dimensionalism is concerned. (shrink)

Precis of my book by this title, for a symposium.

ONTOLOGY This book is a book about the world. I am concerned with ontology, not merely with language. Many ontological treatises concentrate largely on the ...

There is a basic distinction, in the realm of spatial boundaries, between bona fide boundaries on the one hand, and fiat boundaries on the other. The former are just the physical boundaries of old. The latter are exemplified especially by boundaries induced through human demarcation, for example in the geographic domain. The classical problems connected with the notions of adjacency, contact, separation and division can be resolved in an intuitive way by recognizing this two-sorted ontology of boundaries. Bona fide boundaries (...) yield a notion of contact that is effectively modeled by classical topology; the analogue of contact involving fiat boundaries calls, however, for a different account, based on the intuition that fiat boundaries do not support the open/closed distinction on which classical topology is based. In the presence of this two-sorted ontology it then transpires that mereotopology—topology erected on a mereological basis—is more than a trivial formal variant of classical point-set topology. (shrink)

Artificial Intelligence: A Modern Approach, 3e offers the most comprehensive, up-to-date introduction to the theory and practice of artificial intelligence. Number one in its field, this textbook is ideal for one or two-semester, undergraduate or graduate-level courses in Artificial Intelligence. Dr. Peter Norvig, contributing Artificial Intelligence author and Professor Sebastian Thrun, a Pearson author are offering a free online course at Stanford University on artificial intelligence. According to an article in The New York Times, the course on artificial intelligence is (...) “one of three being offered experimentally by the Stanford computer science department to extend technology knowledge and skills beyond this elite campus to the entire world.” One of the other two courses, an introduction to database software, is being taught by Pearson author Dr. Jennifer Widom. Artificial Intelligence: A Modern Approach, 3e is available to purchase as an eText for your Kindle™, NOOK™, and the iPhone®/iPad®. (shrink)

We can see mereology as a theory of parthood and topology as a theory of wholeness. How can these be combined to obtain a unified theory of parts and wholes? This paper examines various non-equivalent ways of pursuing this task, with specific reference to its relevance to spatio-temporal reasoning. In particular, three main strategies are compared: (i) mereology and topology as two independent (though mutually related) chapters; (ii) mereology as a general theory subsuming topology; (iii) topology as a general theory (...) subsuming mereology. Some more speculative strategies and directions for further research are also considered. (shrink)

Die in diesem Band vereinten Aufsätze spiegeln Brentanos späte Ansichten wieder; die Einleitung wurde für den allgemein philosophisch interessierten Leser konzipiert und behandelt Brentanos Theorie des Kontinuums, des Ursprungs des ...

There are conflicting intuitions concerning the status of a boundary separating two adjacent entities (or two parts of the same entity). The boundary cannot belong to both things, for adjacency excludes overlap; and it cannot belong to neither, for nothing lies between two adjacent things. Yet how can the dilemma be avoided without assigning the boundary to one thing or the other at random? Some philosophers regard this as a reductio of the very notion of a boundary, which should accordingly (...) be treated a mere façon de parler. In this paper I resist this temptation and examine some ways of taking the puzzle at face value within a realist perspective—treating boundaries as ontologically on a par with (albeit parasitic upon) extended parts. (shrink)

For most of the history of metaphysics, the subject has been dominated by the concept of substance. There is an everyday commonsense notion of substance which is perfectly harmless and which I shall defend against attempts to remove it or revise it away. But I deny that substance has to be construed as a primitive even in everyday terms. Borrowing Strawson’s distinction between descriptive and revisionary metaphysics, I press the legitimate claims of revisionary metaphysics and argue that there is no (...) place for a fundamental concept of substance within it, although aspects of the concept are likely to find their place therein. (shrink)

1. Many philosophers think that “What is identity across time?” is an important and meaningful question. I have a great deal of trouble seeing what this question might be. But, very often, if one cannot understand a philosophical question, one’s best course is to look at some alleged answers to it; sometimes these answers enable one to see what question it is that they are offered as answers to. The following passage by Michael Tooley is supposed to provide an answer (...) to the question we are trying to get at. (shrink)

Occurrents are entities that exist in time and, with few or no exceptions, extend over time as well, that is, they have parts corresponding to the different times at which they exist. This makes it very easy to say what makes it true that they exist at the times at which they do. Singular existential propositions, being contingent, positive and arguably atomic, stand in need of truth-makers, entities in virtue of whose existence they are true. The obvious candidate for what (...) makes it true that Tony Blair exists is the Right Honourable Member for Sedgefield himself: by virtue of his existing, it is true that he exists. Nothing could be more straightforward. However, things that exist in time, with few exceptions, exist at some times and not at others. So a proposition to the effect that a certain object exists at a certain time likewise stands in need of a truth-maker, one matching the requirements of the existential proposition in question in its temporal specificity. Take an occurrent such as a boxing match and suppose it is going on twenty minutes after starting: by virtue of what is this true? The obvious answer here is that it is by virtue of the existence of that temporal part or phase which extends just over the time in question. Other temporal parts of the same occurrent which do not extend over this time do not act as truth-maker for the temporally specific existential proposition, this one does. There is no problem because occurrents do have temporal parts which can do this job. (shrink)

Are we the people we were? If we are continuants, then the answer to this question is an affirmative one. But it is a moot point whether anything is a continuant. The debate over this issue—of whether there are such things as continuants—is often conducted in the context of theories concerning the apparent passage of time. Thus it has been argued that the tenseless theory of time, according to which time does not really pass, forces us to tear down part (...) of the basis for the intuitive distinction between ordinary, reidentifiable objects on the one hand, and processes on the other, and to regard such objects as mountains as persisting through time in exactly the way that thunderstorms do: by having distinct temporal parts at different times. I confess that I am a tenseless theorist of time, and take that theory to entail such a conclusion about the persistence of objects. But it is not just a certain stance over time’s passage that motivates sympathy towards temporal parts and suspicion of continuants. Thinking of objects as having temporal parts sits more comfortably than does the rival view with two natural assumptions concerning continuity: that beginning and ceasing to exist, at least for most objects, involves underlying changes which are continuous in nature; and that objects exhibit continuity through time, in the sense of not having gaps in their existence. Or so I shall argue in what follows. (shrink)

Every domain-specific ontology must use as a framework some upper-level ontology which describes the most general, domain-independent categories of reality. In the present paper we sketch a new type of upper-level ontology, which is intended to be the basis of a knowledge modelling language GOL (for: 'General Ontological Language'). It turns out that the upper- level ontology underlying standard modelling languages such as KIF, F-Logic and CycL is restricted to the ontology of sets. Set theory has considerable mathematical power and (...) great flexibility as a framework for modelling different sorts of structures. At the same time it has the disadvantage that sets are abstract entities (entities existing outside the realm of time, space and causality), and thus a set-theoretical framework should be supplemented by some other machinery if it is to support applications in the ripe, messy world of concrete objects. In the present paper we partition the entities of the real world into sets and urelements, and then we introduce several new ontological relations between these urelements. In contrast to standard modelling and representation formalisms, the concepts of GOL provide a machinery for representing and analysing such ontologically basic relations. (shrink)