Online research in philosophy

Composition as identity is the strange and strangely compelling doctrine that the whole is in some sense identical to its parts. Kris McDaniel (2008) argues that composition as identity rules out strongly emergent properties. I will argue that one version of the doctrine—namely, the most straightforward, albeit strangest, version—is resistant to the argument in an instructive way. What could it mean to say that one thing (such as a whole) is identical to many things (its parts)? That is indeed the (...) $64,000 question. But however we answer it, McDaniel says, composition as identity had better be taken to imply the following principle. (shrink)

Counterpart theory has come a long way since the seventies. Its virtues are now generally appreciated. It has been extended to temporal discourse.1 And it is less often dismissed out of hand, now that Saul Kripke’s scornful words are no longer regarded as the last on the subject. But new critics have appeared, equally formidable if less dismissive. Counterpart theorists, both modal and temporal, owe them answers.

I will defend what Peter van Inwagen (1990) calls nihilism: the view that nothing is a (proper) part of anything. This formulation needs refining, but it will do for now.1 Nihilism may seem absurd. The world of common sense and science seems, after all, to consist primarily of entities with parts: persons, animals, plants, planets, stars, galaxies, molecules, viruses, rocks, mountains, rivers, tables, chairs, telephones, skyscrapers, cities… But the denial of such entities is not absurd when it is coupled with (...) the acceptance of their simple subatomic particles.2 Consider three subatomic particles, a, b , and c, arranged in a triangular pattern. According to me, there exist only three things here: a, b , and c. According to others, there exists a fourth thing: a triangle, T , which contains a, b , and c as parts. (Forgive my calling T a triangle even though it consists solely of the vertices.) Picture our disagreement thus. (shrink)

Composition as identity is the strange and strangely compelling doctrine that the whole is in some sense identical to its parts. According to the most interesting and fun version, the one inspired by Donald Baxter (1988a,b), this is meant in the most straightforward way: a single whole is genuinely identical to its many parts, in the very same sense of identity, familiar to philosophers, logicians, and mathematicians, in which I am identical to myself and 2 + 2 is identical to (...) 4. Composition as identity implies the principle of Collapse: something is one of the X s iff it is part of the fusion of the X s. (Collapse is so-called because it in effect identifies mereologically equivalent pluralities.) In an earlier paper I pointed out that Collapse alters Boolos’s logic of plural quantification in various ways.1 Here I point out some further consequences of Collapse. For example, collapse implies that plural definite descriptions do not function normally. (As we will see, this undermines Kris McDaniel’s (2008) recent argument against composition as identity.) Also it opens the door to drastic—albeit unattractive— ideological simplifications: parthood, identity, and the plural quantifiers may all be eliminated. (shrink)

According to Eli Hirsch, non-commonsensical ontological claims just couldn’t be true. Oversimplifying: there is strong metasemantic pressure on correct interpretations of natural language to be charitable—to count a sentence as true if ordinary speakers regard it as being obviously true. Ordinary speakers regard sentences like “There is at least one building in New York City” and “Nothing is composed of Socrates’s nose and the Eiffel tower” as being obviously true; and there is no countervailing metasemantic pressure; so correct interpretations count (...) them as true; so they are true. So non-commonsensical ontological views that say otherwise can be seen to be wrong—simply by attending to metasemantics. One source of countervailing metasemantic pressure might be Lewisian reference magnetism. David Lewis (1983, 1984) has argued on independent grounds that metasemantics cannot be based solely on charity, and that another source of metasemantic pressure is “eligibility”: good interpretations must, as much as possible, assign meanings that “carve at the joints”. So one reply to Hirsch, which I offered in my paper “Ontological Realism” and elsewhere, is that i) there are joint-carving meanings that are suitable to be meant by quantifiers; ii) Lewisian reference magnetism is true; and iii) charity is trumped by the eligibility of an interpretation that assigns the joint-carving meanings to the quantifiers.1 I also proposed a backup reply (to which I’m increasingly partial). Suppose that i) is true but either ii) or iii) is false. Suppose, that is, that although there are indeed joint-carving quantifier meanings, either Lewis is wrong that eligibility counts in metasemantics or else eligibility does count but not enough to outweigh charity in this case. Then Hirsch would be right about ontological claims in natural language; but ontology could instead be conducted in “Ontologese”, a language in which quantifiers are stipulated to stand for the joint-carving meanings.. (shrink)

For most us, learning which quantum theory correctly describes human bodies will not affect our attitudes towards our loved ones. On the other hand, a child’s discovery of the nature of meat (or an adult’s discovery of the nature of soylent green) can have a great effect. In still other cases, it is hard to say how one would, or should, react to new information about the underlying nature of what we value—think of how mixed our reactions are to evidence (...) of cultural determinism or atheism, or of how mixed our reactions would be to learning that we all live in the Matrix. (Indeed, maybe there is no objective fact about how we should react. Derek Parfit’s (1984, section 95) fear of death diminished when he became convinced of certain theses about the metaphysics of personal identity. Perhaps there is no objective fact of the matter as to whether this was rational; perhaps it was rational for him but would not be for others.) What can metaphysics contribute to the question of the evil of death? It cannot, on its own, settle the question, since there is no simple rule telling us how to adjust value in light of new information about underlying nature. Given a clear view of the nature of death, there will remain the question of its disvalue. However, metaphysics can help us attain this clear view. Moreover, a clear conception of what metaphysical positions do and don’t say, and a clear conception of how metaphysics works in general, can remove impediments to a rational appraisal of the evil of death. (shrink)

In order to perfectly describe the world, it is not enough to speak truly. In this ambitious and ground-breaking book, Theodore Sider argues that for a representation to be fully successful, truth is not enough; the representation must also use the right concepts--concepts that 'carve at the joints'--so that its conceptual structure matches reality's structure. There is an objectively correct way to 'write the book of the world'. Sider's argument begins from the assertion that metaphysics is about the fundamental structure (...) of reality. Not about what's necessarily true; not about what properties are essential; not about conceptual analysis; and not about what there is. While inquiry into necessity, essence, concepts, or ontology might help to illuminate reality's structure, the ultimate goal is insight into this structure. Sider argues that part of the theory of structure is an account of how structure connects to other concepts. For example, structure can be used to illuminate laws of nature, explanation, reference, induction, physical geometry, substantivity, conventionality, objectivity, and metametaphysics. Another part is an account of how structure behaves. Since structure is a way of thinking about fundamentality, Sider's account implies distinctive answers to questions about the nature of fundamentality. These answers distinguish his theory of structure from other recent theories of fundamentality, including Kit Fine's theory of ground and reality, the theory of truthmaking, and Jonathan Schaffer's theory of ontological dependence. (shrink)

Logic for Philosophy is an introduction to logic for students of contemporary philosophy. It is suitable both for advanced undergraduates and for beginning graduate students in philosophy. It covers (i) basic approaches to logic, including proof theory and especially model theory, (ii) extensions of standard logic that are important in philosophy, and (iii) some elementary philosophy of logic. It emphasizes breadth rather than depth. For example, it discusses modal logic and counterfactuals, but does not prove the central metalogical results for (...) predicate logic (completeness, undecidability, etc.) Its goal is to introduce students to the logic they need to know in order to read contemporary philosophical work. It is very user-friendly for students without an extensive background in mathematics. In short, this book gives you the understanding of logic that you need to do philosophy. (shrink)

In , Peter van Inwagen asked a good question. (Asking the right question is often the hardest part.) He asked: what do you have to do to some objects to get them to compose something---to bring into existence some further thing made up of those objects? Glue them together or what?1 Some said that you don’t have to do anything.2 No matter what you do to the objects, they’ll always compose something further, no matter how they are arranged. Thus we (...) learned of the fusion of the coins in our pockets and the Eiffel tower. (shrink)

This note is to show that a well-known point about David Lewis’s (1986) modal realism applies to Timothy Williamson’s (1998; 2002) theory of necessary existents as well.1 Each theory, together with certain “recombination” principles, generates individuals too numerous to form a set. The simplest version of the argument comes from Daniel Nolan (1996).2 Assume the following recombination principle: for each cardinal number, ν, it’s possible that there exist ν nonsets. Then given Lewis’s modal realism it follows that there can be (...) no set of all (that is, Absolutely All) the nonsets. For suppose for reductio that there were such a set, A; let ν be A’s cardinality; and let µ be any cardinal number larger than ν. By the recombination principle, it’s possible that there exist µ nonsets; by modal realism, there exists a possible world containing, as parts, µ nonsets; each of these nonsets is a member of A. (shrink)

Exotic ontologies are all the rage. Distant from common sense and often science as well, views like mereological essentialism, nihilism, and fourdimensionalism appeal to our desire to avoid arbitrariness, anthropocentrism, and metaphysical conundrums.1 Such views are defensible only if they are materially adequate, only if they can “reconstruct” the world of common sense and science. (No disrespect to the heroic metaphysicians of antiquity, but this world is not just an illusion.) In the world of common sense and science, bicycles survive (...) changes in their parts, billiard balls strike one another, and nothing travels faster than light. The mereological essentialist denies the rst, but offers this replacement: “there exist successions of numerically distinct, but appropriately related, bicycles with different parts” (Chisholm, , chapter ). The nihilist denies the second, but offers this replacement: “there exist X s and Y s such that the X s are arranged billiard-ball-wise, the Y s are also arranged billiard-ball-wise, and the X s strike the Y s”.2 The four-dimensionalist denies the third, but offers this replacement: “no sequences of matter-stages that are related by genidentity travel faster than light”.3 There is room for disagreement over what exactly “reconstruction” amounts to, but at a minimum: when a metaphysical theory reconstructs ordinary sentences φ1. . . as replacement sentences ψ1. . . , ordinary and scienti c evidence must not refute the view that, strictly speaking, it is ψ1. . . rather than φ1. . . that are true. The metaphysician needs reconstruction in order to face the tribunal of experience. An intriguing newcomer to the contemporary scene is the ancient doctrine of monism, the claim that “reality is one”.4 I will argue that, contrary to.. (shrink)

Statues and lumps of clay are said by some to coincide - to be numerically distinct despite being made up of the same parts. They are said to be numerically distinct because they differ modally. Coincident objects would be non-modally indiscernible, and thus appear to violate the supervenience of modal properties on nonmodal properties. But coincidence and supervenience are in fact consistent if the most fundamental modal features are not properties, but are rather relations that are symmetric as between coincident (...) entities, relations such as "opposite-possibly surviving being squashed". (shrink)

In a series of thought-provoking and original essays, eighteen leading philosophers engage in head-to-head debates of nine of the most cutting edge topics in contemporary metaphysics. Explores the fundamental questions in contemporary metaphysics in a series of eighteen original essays - 16 of which are newly commissioned for this volume Features an introductory essay by the editors on the nature of metaphysics to prepare the reader for ongoing discussions Offers readers the unique opportunity to observe leading philosophers engage in head-to-head (...) debate on cutting-edge metaphysical topics Provides valuable insights into the flourishing field of contemporary metaphysics. (shrink)

According to an old and attractive view, vagueness must be eliminated before semantic notions — truth, implication, and so on — may be applied. This view was accepted by Frege, but is rarely defended nowadays.1 This..

Jonathan Schaffer distinguishes two sorts of monism. Existence monists say that only one object exists: The World. Priority monists admit the existence of The World’s parts, but say that their features are derivative from the properties of The World. Both have trouble explaining the features of statespace, the set of possibilities available to The World.

NeoFregeanism is an intriguing but elusive philosophy of mathematical existence. At crucial points, it goes cryptic and metaphorical. I want to put forward an interpretation of neoFregeanism—perhaps not one that actual neoFregeans will embrace—that makes sense of much of what they say. NeoFregeans should embrace quantifier variance.

There will be a few themes. One to get us going: expansion versus contraction. About an object, o, and the region, R, of space(time) in which o is exactly located,1 we may ask: i) must there exist expansions of o: objects in filled superregions2 of R? ii) must there exist contractions of o: objects in filled subregions of..

An introduction to temporal parts theory. Most of us believe in spatial parts: hands are spatial parts of people, an electron is a spatial part of a hydrogen atom, the earth is a spatial part of the solar system. Why are these parts "spatial" parts? Because they are spatially smaller: the hand is spatially smaller than the person, the electron is spatially smaller than the atom, the earth is spatially smaller than the solar system. Temporal parts, then, are parts that (...) are temporally smaller. My current temporal part, "me-today", we might call it, is temporally smaller than me, since it exists today and only today. Temporal parts theory says that objects are made up of temporal as well as spatial parts. (shrink)

One often hears a complaint about “bare particulars”. This complaint has bugged me for years. I know it bugs others too, but no one seems to have vented in print, so that is what I propose to do. (I hope also to say a few constructive things along the way.) The complaint is aimed at the substratum theory, which says that particulars are, in a certain sense, separate from their universals. If universals and particulars are separate, connected to each other (...) only by a relation of instantiation, then, it is said, the nature of these particulars becomes mysterious. In themselves, they do not have any properties at all. They are nothing but a pincushion into which universals may be poked. They are Locke’s “I know not what” (1689, II, xxiii, §2); they are Plato’s receptacles (Timaeus 48c–53c); they are “bare particulars”.1 Against substratum theory there is the bundle theory, according to which particulars are just bundles of universals. The substratum and bundle theories agree on much. They agree that both universals and particulars exist. And they agree that a particular in some sense has universals. (I use phrases like ‘particular P has universal U ’ and ‘particular P ’s universals’ neutrally as between the substratum and bundle theories.) But the bundle theory says that a particular is exhaustively composed of (i.e., is a mereological fusion of) its universals. The substratum theory, on the other hand, denies this. Take a particular, and mereologically subtract away its universals. Is anything left? According to the bundle theory, no. But according to the substratum theory, something is indeed left. Call this remaining something a thin particular. The thin particular does not contain the universals as parts; it instantiates them. (shrink)

Eternalists say that non-present entities (for instance dinosaurs) exist; presentists say that they do not. But some sceptics deny that this debate is genuine, claiming that presentists simply represent eternalists' quantifiers over non-present entities in different notation. This scepticism may be refuted on purely logical grounds: one of the leading candidate ‘presentist quantifiers’ over non-present things has the inferential role of a quantifier. The dispute over whether non-present objects exist is as genuine and non-verbal as the dispute over whether there (...) is life on other planets. (shrink)

Millianism says that the semantic content of a name (or indexical) is simply its referent. This thesis arises within a general, powerful research program, the propositionalist approach to semantics, which sets as a goal for philosophical semantics an assignment of entities — semantic contents — to bits of language, culminating in the assignment of propositions to sentences. Communication, linguistic competence, truth conditions, and other semantic phenomena are ultimately explained in terms of semantic contents. Over 100 years ago Frege (1952/1892) pointed (...) out the problem with Millianism: sentences containing co-referential names seem semantically inequivalent. a=a is trivial, a priori, etc.; a=b is not, even if a and b have the same referent; φ(a) and φ(b) embed differently in the scope of propositional attitude verbs. (shrink)

The core idea of David Armstrong’s combinatorial theory of possibility is attractive. Rearrangement is the key to modality; possible worlds result from scrambling bits and pieces of other possible worlds. Yet I encounter great difficulty when trying to formulate the theory rigorously, and my best attempts are vulnerable to counterexamples. The Leibnizian biconditionals relate possibility and necessity to possible world and true in.

Some say that presentism precludes time travel into the past since it implies that the past does not exist, but this is a bad argument. Presentism says that only currently existing entities exist, and that the only properties and relations those entities instantiate are those that they currently instantiate. This does in a sense imply that the past does not exist. But if that precluded time travel into the past, it would also preclude the one-second-per-second “time travel” into the future (...) that is ordinary persistence, for presentism accords the future the same ontological status as the past. Instead of quantifying over past and future objects and events, presentists speak a tensed language, regimented with primitive sentential tense operators. For a presentist, a persisting person is one who did exist, and who will exist. Regimented, these claims become: it was the case that she exists, and it will be the case that she exists. The presentist may then apply the same strategy to time travel proper. Suppose Katy travels back to the time of the dinosaurs. The presentist can say that it was the case two hundred million years ago that Katy exists. This claim, which consists of a present-tense statement “Katy exists” embedded within the past tense operator it was the case two hundred million years ago that, is exactly the sort of statement about time that a presentist is free to accept. This has all been made clear by Simon Keller and Michael Nelson ( ). In addition to rebutting the bad argument against the consistency of presentism and time travel, Keller and Nelson argue positively in favor of consistency by showing how to translate David Lewis’s ( ) account of time travel into the presentist’s tensed language. The appearance of con ict between presentism and time travel, they argue, is due only to the fact that most defenders of time travel (for example Lewis) have tended to phrase their defenses in nonpresentist terms. As much as I applaud their rebuttal of the bad argument, I wish to sound a note of caution.. (shrink)

Many otherwise reasonable philosophers are impatient with ontology. These philosophers will probably have little time for Objects and Persons, which claims that while there do exist “atoms arranged statuewise”, there do not exist statues; while there do exist atoms arranged tablewise and atoms arranged chairwise, there exist no tables and chairs. Though I join these philosophers, at the end of the day, in rejecting Merricks’s claims, that day is long, whereas they want a quick verdict. But why? Do our impatient (...) friends think that Merricks’s claims are contradictory, analytically false, or otherwise conceptually incoherent? They may say that the conventional meaning of “there exists a statue” is “there exist atoms arranged statuewise”, but this does not stand up to scrutiny. Someone could, of course, just decide to mean such a thing by “there exists a statue”, but then her pronouncements would be irrelevant to Merricks, who intends to be using a.. (shrink)

This is an overview of my book, Four-Dimensionalism. The spatiotemporal metaphysics of Russell, Smart, Quine and Lewis is a blend of separable components concerning time, persistence, mereology, and even semantics, unified by the theme that space and time are analogous: eternalism (past and future objects are just as real as current objects); the reducibility of tense (tensed utterances have tenseless truth conditions; 'now' is an indexical); four-dimensionalism: temporal parts exist; unrestricted composition (all objects, however scattered, have a mereological sum, or (...) fusion), and the "worm view" (continuants, i.e., the objects we normally refer to and quantifier over, are space-time worms, that is, aggregates of temporal as well as spatial parts). My book defends each component except the last. (shrink)

In my book Four-dimensionalism (chapter 4, section 9), I argued that fourdimensionalism – the doctrine of temporal parts – follows from several other premises, chief among which is the premise that existence is never vague. Kathrin Koslicki (preceding article) claims that the argument fails since its crucial premise is unsupported, and is dialectically inappropriate to assume in the context of arguing for four-dimensionalism. Since the relationship between four-dimensionalism and the non-vagueness of existence is not perfectly transparent, I think the argument (...) would retain some interest even if the premise were wholly unsupported; it would show that anyone who accepts that premise (which seems reasonable enough to me though perhaps not to others) must accept four-dimensionalism. Still, Koslicki is right that my defense of the premise was thin. So I will now try to do better. The new defense will have further premises, which could ultimately be rejected by opponents of four-dimensionalism, and so the argument retains the form: anyone who thinks certain things (which seem reasonable enough to me though perhaps not to others) must believe four-dimensionalism. But that’s metaphysics for you. I should also say that, in addition to the material on vague existence, there is more in Koslicki’s excellent paper which I cannot discuss here. I agree with much of it;1 and where we disagree there are formidable challenges, some of which I hope to address in the future. (shrink)

A property, F, is maximal i?, roughly, large parts of an F are not themselves Fs. Maximal properties are typically extrinsic, for their instantiation by x depends on what larger things x is part of. This makes trouble for a recent argument against microphysical superve- nience by Trenton Merricks. The argument assumes that conscious- ness is an intrinsic property, whereas consciousness is in fact maximal and extrinsic.

Logic begins but does not end with the study of truth and falsity. Within truth there are the modes of truth, ways of being true: necessary truth and contingent truth. When a proposition is true, we may ask whether it could have been false. If so, then it is contingently true. If not, then it is necessarily true; it must be true; it could not have been false. Falsity has modes as well: a false proposition that could not have been (...) true is impossible or necessarily false; one that could have been true is merely contingently false. The proposition that some humans are over seven feet tall is contingently true; the proposition that all humans over seven feet tall are over six feet tall is necessarily true; the proposition that some humans are over seven feet tall and under six feet tall is impossible, and the proposition that some humans are over nine feet tall is contingently false. Of these four modes of truth, let us focus on necessity, plus a fifth: possibility. A proposition is possible if it is or could have been true; hence propositions that are either necessarily true, contingently true, or contingently false are possible. Notions that are similar to the modes of truth in being concerned with what might have been are called modal. Dispositions are modal notions, for example the disposition of fragility. Relatedly, there are counterfactual conditionals, for example “if this glass were dropped, it would break.” And the notion of supervenience is modal.1 But let us focus here on necessity and possibility. Modal words are notoriously ambiguous (or at least context-sensitive2). I may reply to an invitation to give a talk in England by saying “I can’t come; I have to give a talk in California the day before”. This use of “can’t” is perfectly appropriate. But it would be equally appropriate for me to say that I could cancel my talk in California (although that would be rude) and give the talk in England instead. What I cannot do is give both talks.. (shrink)

The intimate relationship between X and Y consists in the existence of (metaphysically) necessary truths correlating their occurrences/existences/instantiations. E would be in some sense “overdetermined” if caused by both X and Y.2 Some philosophers say this would be bad, that this cannot or does not happen, that we should construct theories ruling it out, at least in certain cases.3 But why? Given the necessary truths correlating objects and their parts, objects and events concerning those objects, physical and supervenient mental properties, (...) and so on, X and Y do both seem to be causes of E. Should we say that a baseball.. (shrink)

Think of “locations” very abstractly, as positions in a space, any space. Temporal locations are positions in time; spatial locations are positions in (physical) space; particulars are locations in quality space. Should we reify locations? Are locations entities? Spatiotemporal relation- alists say there are no such things as spatiotemporal locations; the fundamental spatial and temporal facts involve no locations as objects, only the instantiation of spatial and temporal relations. The denial of locations in quality space is the bundle theory, according (...) to which particulars do not exist; facts apparently about particulars really concern relations between universals. A “space”, in our abstract sense, consists of a set of objects, together with properties and relations defined on those objects. The objects are the locations of the space, and the distribution of the properties and relations over the locations defines the space’s structure. All spaces are thus quality spaces; when the relations are thought of as spatiotemporal then the space is also a spatiotemporal space. By not reifying locations one denies that these abstract spaces isomorphically represent the real world. The real world does in some sense have a structure that can be non-isomorphically represented by a space (or, more likely, a class of spaces), but the locations in those spaces do not correspond to anything real. We will examine modal considerations on reifying locations. Denying the existence of spatiotemporal locations excludes certain possibilities for spatiotemporal reality. Denying the existence of qualitative locations excludes certain possibilities for qualitative space. In each case the excluded possibilities are pre-analytically possible. Some of the possibilities can be reinstated by modifying the locationless theories, but at the cost of an unattractive holism. Do these modal considerations mandate postulating locations? That depends on whether modal intuition can teach us about the actual world.. (shrink)

A certain conception of Hell is inconsistent with God’s traditional attributes, or so I will argue. My argument is novel in focusing on considerations involving vagueness. The target doctrine of Hell is part of a “binary” conception of the afterlife, by which I mean one with the properties of dichotomy, badness, non-universality, and divine control. Dichotomy: there are exactly two states in the afterlife, Heaven and Hell. After death each person will come to be, determinately, in exactly one of these (...) states. (The doctrine of Purgatory does not violate dichotomy provided everyone in Purgatory eventually ends up in Heaven.) My argument does not apply to a continuous conception of the afterlife, which to my mind is more defensible than the usual binary doctrine. Badness: Hell is very, very bad. Or at least, Hell is much worse than Heaven; for most of the argument this weaker premise will suf ce. More carefully, the premise is that everyone in Heaven is much, much better off than everyone in Hell. Non-universality: some people go to Heaven, and some people go to Hell. I have no objection to Universalists, according to whom everyone goes to Heaven. Nor does my argument apply to those who uphold universal damnation. Divine control: God is in control of the institution of divine judgment, in control of the mechanism or criterion that determines who goes to Heaven and who goes to Hell. This is not to say that God is solely responsible for the fate of created beings, for the divinely mandated criterion might contain a role for free choices. Nor is it to say that God is vindictive. The requirement makes no assumptions about the nature of the criterion, beyond that it is in God’s control. The argument proceeds as follows. Given dichotomy, the only possibilities in the afterlife are determinate membership in either Heaven or Hell; given badness, the second is far worse the rst; and given non-universality, each is populated. Divine control requires that God be in control of the criterion determining these populations, and thus that God’s choice of a criterion be consistent with his attributes. (shrink)

Locke’s view that continuants are numerically distinct from their constituting hunks of matter is popular enough to be called the “standard account”.1 It was given its definitive contemporary statement by David Wiggins in Sameness and Substance2, and has been defended by many since. Baker’s interesting book contributes new arguments for this view, a new definition of ‘constitution’, and a sustained application to persons and human animals. Much of what she says develops this view in new and important ways. But in (...) some cases she does not advance the position, and in others she takes steps backwards. According to Baker, a person is numerically distinct from her constituting animal. One of Baker’s leading arguments is surprisingly unconvincing. Persons differ in important ways from non-human animals. Only persons are moral agents, modify their goals, have wars, culture, etc. If persons were identical to animals—if we were “nothing but animals”, as she puts it—then the manifest discontinuity between humans and non-human animals would be located “within the domain of biology”. “But from a biological point of view, human animals…are biologically continuous with non-human animals.” (p. 17) The argument fails: why should identifying persons with animals preclude saying that these particular animals have radically distinctive features that are of little interest to biologists? The traditional case for non-identity (which Baker accepts) is more powerful: a person and her constituting animal differ by having different persistence conditions. If my memories were transferred to a new body and my old body destroyed, I the person might survive, but the human animal who constituted me would perish. Therefore, before the transfer, I and the animal that constituted me would be numerically distinct but extremely similar things located in exactly the same place. This consequence—the central thesis of the Wiggins view—is surprising: so surprising that some reject the Wiggins view on that basis.. (shrink)

While many are impressed with the utility of possible worlds in linguistics and philosophy, few can accept the modal realism of David Lewis, who regards possible worlds as sui generis entities of a kind with the concrete world we inhabit.1 Not all uses of possible worlds require exotic ontology. Consider, for instance, the use of Kripke models to establish formal results in modal logic. These models contain sets often regarded for heuristic reasons as sets of “possible worlds”. But the “worlds” (...) in these sets can be anything at all; they can be numbers, or people, or sh. The set of worlds, together with the accessibility relation and the rest of the model, is used as a purely formal structure.2 One can even go beyond establishing results about formal systems and apply Kripke models to English, as Charles Chihara has recently argued.3 Chihara shows, for instance, how to use Kripke models (plus primitive modal notions) to give an account of validity for English modal sentences. In other cases worlds are not really needed at all. It is often vivid to give a counterexample thus: “There is a possible world in which P. Since your theory implies that in all worlds, not-P, your theory is wrong.” But the counterexample could just as easily be given using modal operators: “Possibly, P. Since your theory implies that it is necessary that not-P, your theory is wrong.”. (shrink)

In no possible world does a time traveler succeed in killing herearlier self before she ever enters a time machine. So if many,many time travelers went back in time trying to kill theirunprotected former selves, the time travelers would fail inmany strange, coincidental ways, slipping on bananapeels, killing the wrong victim, and so on. Such cases producedoubts about time travel. How could ``coincidences'' beguaranteed to happen? And wouldn't the certainty of coincidentalfailure imply that time travelers are not free to killtheir (...) earlier selves? But if so, what would inhibit theirfreedom? Despite initial appearances, these and other doubtsmay be answered: the possibility of time travel survives yetanother challenge. (shrink)

A property, F, is maximal iff, roughly, large parts of an F are not themselves Fs. Maximal properties are thus extrinsic, for their instantiation by x depends on what larger things x is part of. Maximality makes trouble for a recent analysis of intrinsicality by Rae Langton and David Lewis. Their theory implies that “non-disjunctive” properties are intrinsic if they are independent of “loneliness”; but many ordinary, apparently nondisjunctive, properties satisfy this test but are nevertheless extrinsic in virtue of being (...) maximal. (shrink)

It is easy to become battle-weary in metaphysics. In the face of seemingly unresolvable disputes and unanswerable questions, it is tempting to cast aside one’s sword, proclaiming: “there is no fact of the matter who is right!” Sometimes that is the right thing to do. As a case study, consider the search for the criterion of personal identity over time. I say there is no fact of the matter whether the correct criterion is bodily or psychological continuity.1 There exist two (...) candidate meanings for talk of persisting persons, one corresponding to each criterion, and there is simply no fact of the matter which candidate we mean. An argument schema for this sort of “no fact of the matter” thesis will be constructed. An instance of the schema will be defended in the case of personal identity. But scrutiny of this instance will reveal limits of the schema. Questions not settled by conceptual analysis—in particular, some very difficult questions of fundamental ontology—have answers. So do certain questions that can be settled by conceptual analysis, namely those that would be answered definitively by ideal philosophical inquiry. Whether there is a fact of the matter is not easily ascertained merely by looking to see whether disputes seem unresolvable or questions unanswerable: sometimes the truth is out there, however hard (or even impossible) it may be to discover. (shrink)

Four-Dimensionalism defends the thesis that the material world is composed of temporal as well as spatial parts. This defense includes a novel account of persistence over time, new arguments in favour of the four-dimensional ontology, and responses to the challenges four-dimensionalism faces." "Theodore Sider pays particular attention to the philosophy of time, including a strong series of arguments against presentism, the thesis that only the present is real. Arguments offered in favour of four-dimensionalism include novel arguments based on time travel, (...) the debate between spacetime substantivalists and relationalists, and vagueness. Also included is a comprehensive discussion of the paradoxes of coinciding material objects, and a novel resolution of those paradoxes based on temporal counterpart theory. In conclusion Sider replies to prominent objections to four-dimensionalism, including discussion of the problem of the rotating homogenous disk. (shrink)

André Gallois’s Occasions of Identity injects a refreshing new perspective into an old debate. Actually, what is new is the advocacy of the perspective: Gallois takes up a view that many consider a non-starter, and shows this reaction to be premature. The debate is over the right way to understand the traditional puzzles involving two things being in the same place at the same time; the perspective is that identity can hold temporarily (and contingently). Suppose an amoeba, name it AMOEBA, (...) divides in two. One of the resultant amoebas, POND, lives in a pond; the other, SLIDE, is examined on a slide in a laboratory. Does AMOEBA survive this process, and if so, does it survive as POND or SLIDE? If we stipulate that POND and SLIDE are symmetrically related to AMOEBA then it seems arbitrary to identify AMOEBA with exactly one of POND and SLIDE. But we cannot identify AMOEBA with each, for then by the transitivity and symmetry of identity we would wrongly identify POND and SLIDE. We are left with the conclusion that AMOEBA is identical to neither. But this seems wrong too; surely fission does not result in death. So just what does happen to AMOEBA? How to respond to this and related cases (involving statues and their constituting hunks of matter, cats and their undetached parts, and so on) has been much discussed.1 There are many proposals, each with distinctive strengths and weaknesses. To these Gallois adds his own, which runs as follows. After division, there are two amoebas, POND and SLIDE, each of which existed before division. But it does not follow that there were two amoebas before division. Though POND and SLIDE are numerically distinct after division, they were numerically identical before division. The identity relation can hold temporarily, or occasionally, as Gallois puts it. My sense is that this sort of claim is regarded by most metaphysicians as downright wacky. And yet there is something very natural about it. Why distinguish POND and SLIDE today because they will differ tomorrow? I suspect the “wackiness” reaction has two sources, one based on Leibniz’s Law.. (shrink)

Possible worlds present a formidable challenge for the lover of desert landscapes. One cannot ignore their usefulness; they provide, as David Lewis puts it, “a philosophers’ paradise”.1 But to enter paradise possibilia must be fit into a believable ontology. Some follow Lewis and accept worlds at face value, but most prefer some other choice from the current menu. Part of Chihara’s book is a critical discussion of some of these menu options: Lewis’s modal realism, Alvin Plantinga’s abstract modal realism, (...) Graeme Forbes’s anti-realism and Gideon Rosen’s modal fictionalism. These discussions are very detailed and conversant with the literature. The discussions of Forbes (pp. 142-167) and of paradox within Plantinga’s system (pp. 120-141) are particularly enlightening. The rest of the book is devoted to Chihara’s positive project: developing an account of the status of model theory for non-modal logic, and then applying it to the modal case. The prize is an understanding of possible worlds semantics that requires no commitment to possible worlds at all (beyond the purely formal “possible worlds” of the standard Kripke-models.) What does the relativized notion of truth in an interpretation studied in (non-modal) model theory have to do with plain old truth? Chihara’s answer involves “connecting theorems” that relate truth-in to truth (chapter 5). A “natural-language proto-interpretation of the sentential calculus” (NLPI of SC) is a function that assigns meanings of declarative sentences of English to sentence letters. Where I is an NLPI of SC and φ is a sentence letter, Chihara uses ‘[φ/I ]’ to refer to “φ with the meaning it has been assigned by I ” (p. 191); where φ is not atomic, he says (p. 192). (shrink)

Four-dimensionalism, as I’ll use the term, is the doctrine that reality is spread out in time as well as space.1 Just as objects that are located at multiple regions of space contain parts confined to those regions of space, so objects that are located at multiple regions of time contain parts — temporal parts — that are confined to those regions of time. (Or better: an object that occupies an extended spatiotemporal region R has parts confined to the various subregions (...) of R; but I’ll ignore this complication henceforth.) Most who accept this ontology of perduring objects, as they are often called, identify the continuants of our everyday ontology with “space-time worms” — mereological sums of stages from different times. Elsewhere (1996) I have proposed a different version of four-dimensionalism, which identifies continuants with the stages themselves, and which analyses de re temporal predication with a temporal version of modal counterpart theory (Lewis, 1968, 1971). On this view, a current assertion of ‘Clinton was indiscreet’ is true iff the (current) referent of ‘Clinton’ — a stage — has an indiscreet temporal counterpart in the past. The temporal counterpart relation is the same “genidentity” or “unity” relation used by the worm theorist to unify the successive stages of continuing space-time worms. In my 1996 I supported this view by appeal to its ability to resolve various philosophical puzzles, including the paradoxes of material constitution and Derek Parfit’s (1971) puzzle about identity and what matters; the purpose of the present note is to mention one other line of argument. A widely discussed contemporary argument for temporal parts is David Lewis’s argument from temporary intrinsics, according to which only the fourdimensionalist can explain the phenomenon of intrinsic change.2 I am now straight-shaped, but will fail to be straight-shaped in the future. There is an.. (shrink)

I am now typing on a computer I bought two years ago. The computer I bought is identical to the computer on which I type. My computer persists over time. Let us divide our subject matter in two. There is first the question of criteria of identity, the conditions governing when an object of a certain kind, a computer for instance, persists until some later time. There are secondly very general questions about the nature of persistence itself. Here I include (...) the question of temporal parts, as well as certain familiar paradoxes (e.g., the statue and the lump). Following John Perry (1975, Introduction), let us characterize a criterion of identity over time for F s as a way of filling in φ in the following schema: Stages S1 and S2 belong to some continuing F iff φ Defenders of temporal parts (see below) regard S1 and S2 as being temporal parts of the continuing F ; others regard S1 and S2 as different stages in the life history of the continuing F . Thus each camp can make use of Perry’s formula. It is traditional to divide such criteria into those governing persons and those governing anything else. It is further traditional to say that the criterion of identity over time for non-persons involves spatiotemporal continuity. An excellent discussion is Eli Hirsch’s The Concept of Identity1, which utilizes the notion of continuity under a sortal. Kind-terms, or sortals, are terms that specify what kind of or sort of thing an object is. Examples include ‘tree’, ‘car’, and ‘mountain’. Where F is a sortal, Hirsch’s analysis is roughly that stages belong to the same F iff they are connected by a spatiotemporally and qualitatively continuous sequence of F -stages. Unmodified, this analysis prohibits temporally discontinuous entities, such as a watch that is taken apart and then reassembled. Hirsch discusses the necessary modifications. Spatiotemporal continuity analyses face a problem when applied to the persistence of matter. The literature here has been dominated by discussion of examples provided by David Armstrong (1980) and Saul Kripke (unpublished.... (shrink)

In the process of arguing against all theories of extended material objects made up of simples, Dean Zimmerman has recently argued against the compossibility of continuous closed and continuous open material objects. But it is surely undeniable that point-like material objects are possible; plausible principles of recombination and the principle of unrestricted composition then lead to the possibility Zimmerman rejects. Fortunately, Zimmerman's arguments (inspired by Brentano's remarks on the concept of contact) can be resisted: what appear to be implausible modal (...) consequences of the compossibility of open and closed continuous material objects turn out to be merely the results of a decision to use `material object' in a certain way. (shrink)

The existence and importance of supervenience principles for identity across times and worlds have been noted, but insufficient attention has been paid to their precise nature. Such attention is repaid with philosophical dividends. The issues in the formulation of the supervenience principles are two. The first involves the relevant variety of supervenience: that variety is global, but there are in fact two versions of global supervenience that must be distinguished. The second involves the subject matter: the names “identity over time” (...) and “identity across worlds” are misnomers, for in neither case is identity at issue. The philosophical dividends then follow. Nathan Salmon’s argument that identity over time needs no “grounds” in matters of qualitative fact can be answered, as can an argument offered by many, that coincident objects (such as statues and lumps of clay) would require objectionably ungrounded differences in identities across times and worlds. (shrink)

Michael Jubien’s Ontology, Modality, and the Fallacy of Reference is an interesting and lively discussion of those three topics. In ontology, Jubien defends, to a first approximation, a Quinean conception: a world of objects that may be arbitrarily sliced or summed. Slicing yields temporal parts; summing yields aggregates, or fusions. Jubien is very unQuinean in his explicit Platonism regarding properties and propositions, but concerns about abstracta are peripheral to much of the argumentation in the book.1 His version of the doctrine (...) that arbitrary mereological sums exist is nonstandard in that he views it as a convention (albeit a useful one) that we treat sums of objects as themselves being objects. Indeed, he views the concept of objecthood itself as being conventional. The world consists fundamentally of stuff, which we divide into things in any way that suits our purposes. In modality, Jubien’s views are to a first approximation Chisholmian: he holds the doctrine of mereological essentialism, according to which anything.. (shrink)

Presentism is the doctrine that only the present is real. Since ordinary talk and thought are full of quantification over non-present objects, presentists are in a familiar predicament: in their unreflective moments they apparently commit themselves to far more than their ontological scruples allow. A familiar response is to begin a project of paraphrase. Truths appearing to quantify over problematic entities are shown, on analysis, to not involve quantification over those entities after all. But I think that we might be (...) better off abandoning paraphrase altogether. I suggest a project of discovering “underlying truths” rather than paraphrases. I will explore this strategy as applied to defending presentism, but my hope is that lovers of desert landscapes everywhere will herein find words of comfort. (shrink)

In an article in Scientific American (March 1994, pp. 68–74) entitled “The Quantum Physics of Time Travel”, Oxford physicist David Deutsch and Oxford philosopher Michael Lockwood give a defense of the physical possibility of time travel based on the “Many Worlds” interpretation of quantum mechanics. This positive view of theirs is not my concern, however—I want to quarrel with their argument that time travel cannot be accommodated in any other way.1 The best way to spell out the traditional “grandfather paradox” (...) that appears to threaten the possibility of time travel involves the notion of ability, or personal possibility, or free will. An example of David Lewis’s: Tim travels back in time with the intent to kill his grandfather.2 Let us fix the case as one in which Tim in fact will not kill Grandfather; still, it seems that he can kill Grandfather because he is a good shot, has a gun, and is alone with Grandfather at close range. As Lewis says, Tim “has what it takes” to kill Grandfather. However, it is also compelling that Tim cannot kill Grandfather, because if Grandfather had been killed in his youth, Tim would not have existed to kill him. It is important to realize that the paradox essentially involves the notion of ability. No inconsistency results from supposing that Tim does not kill Grandfather. As for the case in which Tim does kill Grandfather, there are various possibilities. We could tell a consistent time travel story in which Tim kills Grandfather, but Grandfather is miraculously resurrected. Or one in which Tim kills Grandfather, but in which Grandfather has already had a child. Or one in which Tim kills Grandfather permanently, before Grandfather has any children, but in which Tim’s grandfather is someone other than Grandfather. As for the story in which Tim both kills Grandfather permanently in such a way that Grandfather has no children, and also is descended from Grandfather, this is an inconsistent time travel story; but of course the existence of some.... (shrink)

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)

Some philosophers believe that everyday objects are 4-dimensional spacetime worms, that a person (for example) persists through time by having temporal parts, or stages, at each moment of her existence. None of these stages is identical to the person herself; rather, she is the aggregate of all her temporal parts.1 Others accept “three dimensionalism”, rejecting stages in favor of the notion that persons “endure”, or are “wholly present” throughout their lives.2 I aim to defend an apparently radical third view: not (...) only do I accept person stages; I claim that we are stages.3 Likewise for other objects of our everyday ontology: statues are statue-stages, coins are coin-stages, etc. At one level, I accept the ontology of the worm view. I believe in spacetime worms, since I believe in temporal parts and aggregates of things I believe in. I.. (shrink)

An intrinsic property, as David Lewis puts it, is a property "which things have in virtue of the way they themselves are", as opposed to an extrinsic property, which things have "in virtue of their relations or lack of relations to other things".1 Having long hair is an intrinsic property; having a long-haired brother is not. Intuitive as this notion is (and valuable in doing philosophy, I might add), it seems to resist analysis. Analysis, that is, to “quasi-logical” notions such (...) as necessity, spatiotemporal location: using stronger tools, Lewis has given an analysis of intrinsicality that I take to be roughly correct. Lewis initially described intrinsic properties in his 1983 paper "Extrinsic Properties" as follows. (shrink)

Peter Forrest and D.M. Armstrong have given an argument against a theory of naturalness proposed by David Lewis based on the fact that ordered pairs can be constructed from sets in any of a number of different ways. 1. I think the argument is good, but requires a more thorough defense. Moreover, the argument has important consequences that have not been noticed. I introduce a version of Lewis’s proposal in section one, and then in section two I present and defend (...) my version of the argument. After addressing a worry about my argument in section three, in section four I argue that a similar “argument from arbitrariness” jeopardizes Lewis’s solution to the Kripke/Wittgenstein puzzle of the content of thought. (shrink)

In the past fifteen years or so there has been a lot of attention paid to theories of “sparse” universals, particularly because of the work of D. M. Armstrong. These theories are of particular interest to those of us concerned with the distinction between natural and non-natural properties, since, as David Lewis has observed, it seems possible to analyze naturalness in terms of sparse universals. Moreover, Armstrong claims that we should conceive of universals as being “immanent” as opposed to “transcendent”, (...) and if universals are immanent then, as we will see, there is pressure to admit they are sparse as well. But I will argue that neither of these alleged reasons to accept a sparse conception of universals succeeds: the outlook for a fully general analysis of naturalness in terms of universals is not good, and the apparent advantages of immanence over transcendence are illusory. (shrink)

Some contemporary Russellians, defenders of the view that the semantic content of a proper name, demonstrative or indexical is simply its referent, are prepared to accept that view’s most infamous apparent consequence: that coreferential names, demonstratives, indexicals, etc. are intersubstitutable salva veritate, even in intentional contexts. Nathan Salmon and Scott Soames argue that our recalcitrant intuitions with respect to the famous apparent counterexamples are not semantic intuitions, but rather pragmatic intuitions. Strictly and literally speaking, Lois Lane believes, and even knows (...) that Clark Kent is identical to Superman, since she believes and knows that Superman is identical to Superman. Salmon and Soames attempt to soften our reaction to this shocker by allowing that it is typically misleading to utter the sentence ‘Lois Lane knows that Clark Kent is identical to Superman’, since it pragmatically implicates, without semantically entailing, that Lois Lane would accept the sentence ‘Clark Kent is identical to Superman’. Our compulsive tendency to claim that ‘Lois Lane knows that Clark Kent is Superman’ is false, rather than merely misleading, is due to a confusion between semantics and pragmatics, between truth conditions and conditions of appropriateness of utterance.1 It is probably fair to say that the common reaction to this move in defense of Russellianism is negative. Mark Richard says the following. (shrink)

is an important principle, worthy of serious scrutiny. Its truth or falsity bears on the question of whether moral rightness, obligatoriness, etc., are a matter of factors “internal” to an agent (such as motives and beliefs), or whether “external” factors (such as consequences) are relevant to determining the moral normative status of acts. Moreover, Access enjoys considerable intuitive support. If I destroy Greensboro in professor Sorensen’s example by pushing the wrong button, I seem to have a good excuse to give (...) to anyone who would accuse me of wrongdoing: “I had no way of knowing that this action would be wrong!” But if I have a good excuse, then pushing the button doesn’t seem wrong; and if that action isn’t wrong, then I had no obligation to refrain from pushing that button. A principle distinct from, but analogous to, Access also deserves our attention. (shrink)

Recent discussions of consequentialism have drawn our attention to the so-called “self-other” asymmetry. Various cases presented by Michael Slote and Michael Stocker are alleged to demonstrate a fundamental asymmetry between our obligations to others and ourselves.1 Moreover, these cases are taken to constitute a difficulty for consequentialism, and for the various versions of utilitarianism in particular. I agree that there is a fundamental asymmetry between our obligations to ourselves and to others, and that this fact is inconsistent with the letter (...) of traditional utilitarianisms. However, I do not think this represents a deep shortcoming of the spirit behind utilitarianism. In this paper I will argue that the self-other asymmetry can be accommodated in a broadly utilitarian framework. First, in section one, I characterize moral “asymmetry” in general. Then, in section two, I argue that the cases presented by Slote and Stocker do indeed represent a genuine self-other asymmetry. In part, this involves criticism of an attempt to accommodate the asymmetry within a preferentist framework. Finally, I will present my own solution to the problem of self and other. (shrink)

This dissertation explores the concepts of naturalness, intrinsicality, and duplication. An intrinsic property is had by an object purely in virtue of the way that object is considered in itself. Duplicate objects are exactly similar, considered as they are in themselves. The perfectly natural properties are the most fundamental properties of the world, upon which the nature of the world depends. In this dissertation I develop a theory of intrinsicality, naturalness, and duplication and explore their philosophical applications. Chapter 1 introduces (...) the notions, gives a preliminary survey of some proposed conceptual connections between the notions, and sketches some of their proposed applications. Chapter 2 gives my background assumptions and introduces notational conventions. In chapter 3 I present a theory of naturalness. Although I take ‘natural’ as a primitive, I clarify this notion by distinguishing and explicating various conceptions of naturalness. In chapter 4 I give a theory of various notions related to naturalness, especially intrinsicality and duplication. I show that ‘intrinsic’ and ‘duplicate’ are interde nable, and then give analyses of these and other notions in terms of naturalness. If, as I think likely, naturalness cannot be analyzed, then what is the proper response? David Lewis suggests: accept naturalness as a primitive. I am sympathetic to this proposal, but not to the form Lewis gives it: chapter 5 contains an argument against Lewis’s theory of naturalness. In chapter 6 I reject the idea that naturalness is analyzable in terms of immanent universals. I focus on the work of D. M. Armstrong. I also criticize Armstrong’s arguments against transcendent universals. (shrink)

We often speak of an object being composed of various other objects. We say that the deck is composed of the cards, that a road is the sum total of its sections, that a house is composed of its walls, ceilings, floors, doors, etc. Suppose we have some material objects. Here is a philosophical question: what conditions must obtain for those objects to compose something? In his recent book Material Beings, Peter van Inwagen addresses this question, which he calls the (...) ‘special composition question’; his answer is:1 (1) For any material objects X , the X s compose something iff the activity of the X s constitutes a life, or there is only one of the Xs. Additionally, he accepts a simpler thesis that follows from (1):2 (2) Every material object is either a mereological atom or a living thing, where a mereological atom is an object lacking proper parts. (2) may seem radical. If it is true then there are no tables, chairs, planets, protons, galaxies, gas stations, etc. But van Inwagen does not hold it lightly— there are serious difficulties with alternate views. Moreover, he claims that.. (shrink)

Nonreductive materialism is the dominant position in the philosophy of mind. The global supervenience of the mental on the physical has been thought by some to capture the central idea of nonreductive materialism: that mental properties are ultimately dependent on, but irreducible to, physical properties. But Jaegwon Kim has argued that global psychophysical supervenience does not provide the materialist with the desired dependence of the mental on the physical, and in general that global supervenience is too weak to be an (...) interesting dependence relation. We argue that these arguments are unsound. Along the way, we clarify the relationship between global and strong supervenience, and show clearly what sort of dependence global supervenience provides. (shrink)

In response to various shortcomings of regularity theories of natural law, some philosophers of a realist bent have recently been drawn to the view that a law of nature is a relation between universals. Heading this group are Michael Tooley and D. M. Armstrong.

Act Utilitarianisms divide into Total and Average versions. Total versions seem to imply Parfit’s “Repugnant Conclusion”. Average versions are proposed in part to avoid the Repugnant Conclusion, but these are subject to “Mere Addition” arguments as detailed by Hudson in “The Diminishing Marginal Value of Happy People”. Thus, various intermediate versions of utilitarianism, such as the one investigated by Hurka in “Value and Population Size”, take on interest. But Hudson argues that such compromise theories are subject to the mere addition (...) arguments, and are therefore no improvement over Average Utilitarianism. I disagree: some such compromise solutions escape Hudson’s Mere Addition arguments. (shrink)