A version of this paper appears in Zimmerman, Dean W. (ed.) Oxford Studies in Metaphysics, Volume 1 (Oxford University Press, 2004), pp. 47--‐‐82. It's reprinted in Michael Rea (ed.), Arguing About Metaphysics (Routledge, 2009); and in Sally Haslanger and Roxanne Marie Kurtz (eds.), Persistence: Contemporary Readings (MIT Press, 2006). A DEFENSE OF PRESENTISM∗ Ned Markosian 1 Introduction Presentism is the view that only present objects exist.1 According to Presentism, if we were to make an accurate list of all the things that exist – i.e., ∗ Apologies to Mark Hinchliff for stealing the title of his dissertation. (See Hinchliff, A Defense of Presentism. As it turns out, however, the version of Presentism defended here is different from the version defended by Hinchliff. See Section 3.1 below.) 1 More precisely, it is the view that, necessarily, it is always true that only present objects exist. At least, that is how I am using the name 'Presentism'. Quentin Smith has used the name to refer to a different view; see his Language and Time. Note that, unless otherwise indicated, what I mean by 'present' is temporally present, as opposed to spatially present. For discussions of Presentism and Non--‐‐presentism, see Adams, "Time and Thisness"; Augustine, Confessions; Bigelow, "Presentism and Properties"; Brogaard, "Presentist Four--‐‐Dimensionalism"; Chisholm, On Metaphysics; Chisholm, "Referring to Things That No Longer Exist"; Christensen, Space--‐‐Like Time; Fine, "Prior on the Construction of Possible Worlds and Instants"; Fitch, "Does Socrates Exist?"; Fitch, "Singular Propositions in Time"; Hinchliff, A Defense of Presentism; Hinchliff, "The Puzzle of Change"; Keller and Nelson, "Presentists Should Believe in Time Travel"; Long and Sedley, The Hellenistic Philosophers, Volume 1, Translations of the Principal Sources with Philosophical Commentary (especially the writings of Sextus Empiricus); Lucretius, On the Nature of the Universe; Markosian, "The 3D/4D Controversy and Non--‐‐present Objects"; McCall, A Model of the Universe; Merricks, "On the Incompatibility of Enduring and Perduring Entities"; Monton, "Presentism and Spacetime Physics"; Prior, "Changes in Events and Changes in Things"; Prior, "The Notion of the Present"; Prior, Papers on Time and Tense; Prior, Past, Present and Future; Prior, "Some Free Thinking About Time"; Prior, "A Statement of Temporal Realism"; 2 a list of all the things that our most unrestricted quantifiers range over – there would be not a single non--‐‐present object on the list. Thus, you and I and the Taj Mahal would be on the list, but neither Socrates nor any future grandchildren of mine would be included.2 And it's not just Socrates and my future grandchildren, either – the same goes for any other putative object that lacks the property of being present. All such objects are unreal, according to Presentism. According to Non--‐‐presentism, on the other hand, non--‐‐present objects like Socrates and my future grandchildren exist right now, even though they are not currently present.3 We may not be able to see them at the moment, on this view, and they may not be in the same space--‐‐time vicinity that we find ourselves in right now, but they should nevertheless be on the list of all existing things. I endorse Presentism, which, it seems to me, is the "common sense" view, i.e., the one that the average person on the street would accept. But there are some serious problems facing Presentism. In particular, there are certain embarrassingly obvious objections to the view that are not easily gotten around. The aims of this paper are (i) to spell out the most obvious objections Prior, Time and Modality; Prior and Fine, Worlds, Times and Selves; Sextus Empiricus, Against the Physicists; Sider, "Presentism and Ontological Commitment"; Sider, Four--‐‐ Dimensionalism; Smith, Language and Time; Smith, "Reference to the Past and Future"; Tooley, Time, Tense, and Causation; Wolterstorff, "Can Ontology Do Without Events?"; and Zimmerman, "Persistence and Presentism". 2 I am assuming that each person is identical to his or her body, and that Socrates's body ceased to be present – thereby going out of existence, according to Presentism – shortly after he died. Those philosophers who reject the first of these assumptions should simply replace the examples in this paper involving allegedly non--‐‐present people with appropriate examples involving the non--‐‐present bodies of those people. 3 Let us distinguish between two senses of 'x exists now'. In one sense, which we can call the temporal location sense, this expression is synonymous with 'x is present'. The Non--‐‐presentist will admit that, in the temporal location sense of 'x exists now', it is true that no non--‐‐present objects exist right now. But in the other sense of 'x exists now', which we can call the ontological sense, to say that x exists now is just to say that x is now in the domain of our most unrestricted quantifiers, whether it happens to be present, like you and me, or non--‐‐present, like Socrates. When I attribute to Non--‐‐ presentists the claim that non--‐‐present objects like Socrates exist right now, I mean to commit the Non--‐‐presentist only to the claim that these non--‐‐present objects exist now in the ontological sense (the one involving the most unrestricted quantifiers). 3 that can be raised against Presentism and (ii) to show that these objections are not fatal to the view. In Section 2 I will spell out the embarrassing problems facing Presentism that I will be concerned with, and in Section 3 I will consider various possible solutions to those problems, rejecting some but endorsing others. 2 Problems for Presentism 2.1 Singular Propositions and Non--‐‐present Objects One of the most obvious problems facing Presentism concerns singular propositions about non--‐‐present objects.4 A singular proposition depends for its existence on the individual object(s) it is about. Thus, Presentism entails that there are no singular propositions about non--‐‐present objects.5 This is a very counterintuitive consequence. Most of us would have thought that there are many propositions about specific non--‐‐present objects (like Socrates, for example). And it seems clear that a proposition that is specifically about a non--‐‐present object would count as a singular proposition about that object. Thus it is natural to think that sentence (1), for example, expresses a singular proposition about Socrates. (1) Socrates was a philosopher. Similarly, most of us would have thought that we often believe singular propositions about non--‐‐present objects, like the proposition that is apparently expressed by (1). But according to Presentism, there are never any singular propositions about non--‐‐present objects, and hence no sentence ever expresses any such 4 In what follows I'll adopt Robert M. Adams's definition of 'singular proposition', according to which "a singular proposition about an individual x is a proposition that involves or refers to x directly, perhaps by having x or the thisness of x as a constituent, and not merely by way of x's qualitative properties or relations to other individuals." (Adams, "Time and Thisness", p. 315.) By the "thisness" of x Adams means "the property of being x, or the property of being identical with x." I will refer to such a property below as x's haecceity. 5 Adams would disagree; he maintains that there are singular propositions about past objects even though those past objects no longer exist. See Section 3.4 below. 4 proposition, and no person ever believes any such proposition. This is surely a strange consequence of Presentism.6 Here is a variation on the same problem. Consider the time when Socrates ceased to be present. According to Presentism, Socrates went out of existence at that time. Thus, according to Presentism, all singular propositions about Socrates also went out of existence at that time. Now consider someone – Glaucon, say – who knew Socrates, and believed various singular propositions about him in the period right before Socrates ceased to be present, but who was unaware of Socrates's unfortunate demise. When Socrates ceased to be present and thereby popped out of existence, according to Presentism, all of those singular propositions about him also popped out of existence. But there was poor Glaucon, who we can suppose did not change in any important intrinsic way when Socrates ceased to be present. According to Presentism, although Glaucon did not change in any significant intrinsic way when Socrates ceased to be present, he nevertheless did undergo a very important change right at that moment: Glaucon all of a sudden went from believing all of those singular propositions about Socrates to not believing any of them – through no fault of his own and without any knowledge that his beliefs were changing in such a dramatic way! Isn't that a strange and absurd consequence of the view? 2.2 Relations Between Present and Non--‐‐present Objects There is more. If there are no non--‐‐present objects, then no one can now stand in any relation to any non--‐‐present object. Thus, for example, you cannot now stand in the relation being an admirer of to Socrates, I cannot now stand in the relation being a grandson of to my paternal grandfather, and no event today can stand in any causal relation to George Washington's crossing the Delaware. These are all fairly counterintuitive consequences of Presentism, and it must be acknowledged that they pose serious problems for the view.7 6 Greg W. Fitch is an example of someone who rejects Presentism for this reason. See Fitch, "Singular Propositions in Time". 7 W.V. Quine is an example of a philosopher who rejects Presentism because of the problem of relations between present and non--‐‐present objects. See his Quiddities, pp. 197--‐‐198. 5 2.3 Presentism and Special Relativity A third challenge for Presentism comes from an empirical theory in physics, namely, the Special Theory of Relativity. It is apparently a consequence of that theory that there is no such thing as absolute simultaneity, and this suggests that which things are present is a relativistic matter that can vary from one reference frame to another. This in turn suggests that the Presentist is committed to the claim that what exists is a relativistic matter, so that it may well be the case that Socrates exists relative to your frame of reference but does not exist relative to my frame of reference. This would surely be an untenable consequence of the view. 2.4 Past and Future Times Here is the fourth embarrassing problem for Presentism that I will discuss in this paper. It is very natural to talk about times. We often speak as if times are genuine entities, and we often appear to express propositions about times. But Presentism seems to entail that there is no time except the present time. Thus Presentism also seems to entail that there are no propositions about any non--‐‐ present times, and that we never say anything about any such times. These would be very odd consequences of Presentism, to say the least. If they are indeed consequences of the view, then some account of why they are not completely unacceptable is needed. And if they are not consequences of the view, then some explanation of this fact is required. For discussions of the special version this problem that has to do with causation, see Bigelow, "Presentism and Properties"; Tooley, Time, Tense, and Causation; and Zimmerman, "Chisholm and the Essences of Events". Tooley rejects Presentism because of the causal version of the problem, while Bigelow and Zimmerman propose solutions to the causal version of the problem that are inspired by the writings of Lucretius and the Stoics. (See Lucretius, On the Nature of the Universe; Sextus Empiricus, Against the Physicists; and Long and Sedley, The Hellenistic Philosophers, Volume 1, Translations of the Principal Sources with Philosophical Commentary (especially the writings of Sextus Empiricus).) (It should be noted, however, that Bigelow's proposed solution to the causal version of the problem seems to require the existence of singular propositions about non--‐‐present objects.) 6 3 Presentist Solutions to these Problems 3.1 Non--‐‐existent Objects that Have Properties and Stand in Relations Let me begin my discussion of responses to these problems by mentioning some possible solutions that I do not endorse. One response available to the Presentist for dealing with both the problem of singular propositions about non--‐‐present objects and the problem of relations between present and non--‐‐ present objects (and perhaps the problem of past and future times as well) involves a view that has been advocated by Mark Hinchliff.8 Hinchliff distinguishes between Serious Presentism and Unrestricted Presentism. Serious Presentism is the conjunction of Presentism with the claim that an object can have properties, and stand in relations, only when it exists, while Unrestricted Presentism is the conjunction of Presentism with the claim that an object can have properties, and stand in relations, even at times when it does not exist. Thus, according to Unrestricted Presentism, Socrates can now have properties like having been a philosopher, and can stand in the admired by relation to me, even though he no longer exists. Moreover, according to Unrestricted Presentism, we can now express singular propositions about Socrates (such as the proposition expressed by (1)), even though Socrates does not exist. There is a great deal to be said for this response to our problems. But the response comes with a price – namely, accepting the claim that an object can have properties, and stand in relations, at a time when it does not exist – that I personally am not willing to pay. That is, my pre--‐‐philosophical intuitions commit me not only to Presentism but also to Serious Presentism. This is of course not meant to be an argument against Unrestricted Presentism. But it does mean that the response to these two problems that is available to the Unrestricted Presentist is not available to me. 3.2 No Singular Propositions Another solution available to the Presentist for dealing with the problem of singular propositions about non--‐‐present objects would be simply to deny that there are any singular propositions about concrete objects in the first place. I 8 See Hinchliff, A Defense of Presentism, Chapters 2 and 3, and "The Puzzle of Change", pp. 124--‐‐126. 7 don't know of any Presentist who adopts this position specifically for the purpose of defending Presentism, but the view that there are no singular propositions about concrete objects has been discussed by Chisholm (who was in fact a Presentist) and various others.9 One who says that there are no singular propositions about concrete objects at all will have to give an account of sentences that seem to express singular propositions about such objects, like the following. (2) Peter van Inwagen is a philosopher. For example, such a person could say that (2) expresses the same general proposition as (2a) (∃x)(x is the referent of 'Peter van Inwagen' and x is a philosopher). Instead of involving van Inwagen himself, or referring directly to him, this proposition involves the property of being the referent of 'Peter van Inwagen' (as well as the property of being a philosopher and the relation of coinstantiation). If the Presentist insists that there are no singular propositions about concrete objects at all, not even singular propositions about present concrete objects, then he or she can say that there is nothing peculiar about maintaining that sentences that appear to express singular propositions about past or future concrete objects really express general propositions about the way things were or will be. For on this view, even when Socrates was present the sentence (3) Socrates is a philosopher did not express any singular proposition about Socrates. Instead, it expressed some general proposition like the one expressed by the following sentence. (3a) (∃x)(x is the referent of 'Socrates' and x is a philosopher). 9 See, for example, Chisholm, The First Person. 8 Thus there is nothing odd about saying that (1) does not now express a singular proposition about Socrates. Instead, the Presentist might say, what (1) really expresses is the past--‐‐tensed version of the proposition expressed by (3a), which proposition can be more perspicuously expressed by the following sentence (in which 'P' is the past--‐‐tense sentential operator, short for 'it has been the case that'). (1a) P(∃x)(x is the referent of 'Socrates' and x is a philosopher). Similarly, a Presentist who does not believe in singular propositions about concrete objects in the first place will say that there was no immediate change in Glaucon's beliefs brought about by Socrates's ceasing to be present, since all of Glaucon's beliefs "about" Socrates involved purely general propositions all along. Unfortunately, however, this no--‐‐singular--‐‐propositions--‐‐about--‐‐concrete--‐‐ objects strategy is not appealing to me, for one main reason: it presupposes a controversial thesis – that there are no singular propositions about concrete objects – that I am not willing to endorse. It seems pretty clear to me that there are in fact singular propositions about existing concrete objects (such as the singular proposition that Peter van Inwagen is a philosopher), that many sentences express such propositions, and that many of us often believe such propositions. 3.3 Singular Propositions with Blanks Another response to the problem of singular propositions about non--‐‐present objects would involve appealing to a view about empty names that has been developed by Kaplan, Adams and Stecker, Braun, Salmon, and Oppy.10 I cannot do justice to the view in question in the limited space I have here, but the basic idea is that a sentence with an empty name in it, like 'Harry Potter wears glasses', expresses just the kind of singular proposition that a similar sentence with a normal name (such as 'Woody Allen wears glasses') expresses, except that the singular proposition expressed by the sentence with 10 See Kaplan, "Demonstratives"; Adams and Stecker, "Vacuous Singular Terms"; Braun, "Empty Names"; Salmon, "Nonexistence"; and Oppy, "The Philosophical Insignificance of Gödel's Slingshot". 9 the empty name contains a blank where the other singular proposition contains an individual.11 A Presentist who took this line could say that sentences like (1) do indeed express singular propositions, albeit singular propositions with blanks in them rather than ordinary singular propositions. Although I think that there is a lot to be said for the singular--‐‐propositions--‐‐ with--‐‐blanks view as a theory about empty names, I do not think that the view is of much use to the Presentist when it comes to our current problem. The reason is that combining Presentism with the singular--‐‐propositions--‐‐with--‐‐ blanks view yields the result that the sentences 'Socrates was a philosopher' and 'Beethoven was a philosopher' express the same singular proposition (namely, the singular proposition that _______ was a philosopher). And if the goal of the Presentist is to give some account of sentences like (1) that has plausible consequences regarding the meanings and truth values of those sentences, this result will clearly not do. 3.4 Haecceities to the Rescue? A fourth strategy for dealing with the problem of singular propositions about non--‐‐present objects would be to appeal to unexemplified haecceities. Haecceities are supposed to be properties like the property of being identical to Socrates, each of which can be exemplified only by one unique object. Those who believe in haecceities typically believe that a haecceity comes into existence with its object, and continues to exist as long as it is exemplified by that object. That much is relatively uncontroversial. But some Presentists also believe that a haecceity continues to exist even after its object ceases to exist. On this view, which has been defended by Robert Adams, there is a property – Socrates's haecceity, which we might call "Socraticity" – that came into existence with Socrates and was uniquely exemplified by Socrates, and that continues to exist today, even though it is no longer exemplified.12 Thus, according to Adams, sentences like (1) do express singular propositions about the relevant concrete objects after all, even though those concrete objects no longer exist. The idea is that a sentence like (1) now expresses the proposition 11 For the sake of simplicity, I am now talking as if singular propositions literally contained the individuals they are about, as opposed to merely referring to them directly in some way. 12 See Adams, "Time and Thisness". 10 that there was a unique x who exemplified Socraticity and who was a philosopher, and that this proposition somehow involves or directly refers to Socrates, in virtue of having Socraticity as a constituent. (It is worth noting here that Adams believes in unexemplified haecceities of past objects, but not of future objects. Thus, Adams's version of the haecceity approach purports to solve the problem of singular propositions about non--‐‐present objects for the case of past objects but not for the case of future objects. On his view, there are no singular propositions about future objects.) Unfortunately, there are several problems with the haecceity approach. One problem with the approach, at least as it is defended by Adams, is that, although it allows us to say that there are now singular propositions about past objects, like Socrates, it does not allow us to say that there are now any singular propositions about future objects, like my first grandson.13 Thus, Adams's version of the haecceity approach to the problem of singular propositions about non--‐‐present objects involves an important asymmetry between the past and the future. And it seems to me that any adequate Presentist solution to the problem should treat the past and the future as perfectly analogous.14 A second, and more serious problem with the haecceity approach is that it requires an ontological commitment to the haecceities of nonexistent objects, and the claim that there are such things is a controversial claim that many Presentists, including myself, are not willing to accept. If we are to understand Socraticity as the property of being identical to Socrates, for example, then it seems that Socrates must be a constituent of Socraticity. But in that case, it's hard to see how Socraticity could continue to exist after Socrates goes out of existence.15 13 Since Adams doesn't believe in haecceities of future individuals. 14 Adams responds to this objection in "Time and Thisness". See pp. 319--‐‐320. 15 Adams suggests that individuals are not constituents of their haecceities. (See "Time and Thisness", p. 320.) But I have a hard time understanding how Socrates could fail to be a constituent of Socraticity, although, admittedly, what we say about this matter depends partly on what we say about the tricky subject of the nature of constituency. In any case, whatever we say about the nature of constituency, it seems clear to me that this principle will be true: The property of being identical with x exists only if x itself exists. For it seems to me that for any relation and for any object, the property of standing in that relation to that object will exist only if the object exists. 11 A third problem facing the haecceity approach is that it is not at all clear that the proposition that there was a unique x that exemplified Socraticity and that was a philosopher is really a singular proposition about Socrates. That is, it's not clear that this proposition involves or refers to Socrates directly. Consider the proposition that there was a unique x that was Plato's best teacher and that was a philosopher. That proposition is not a singular proposition about Socrates. And it seems to me that these two propositions are alike in this respect, so that if the one is not a singular proposition about Socrates then neither is the other. After all, what is the difference between Socraticity and the property of being Plato's best teacher in virtue of which a proposition containing the former property is a singular proposition about Socrates while a proposition containing the latter property is not? Finally, there is a fourth problem with this approach that combines the second and third problems to generate a dilemma for the haecceity approach. Either the proposition that there was a unique x that exemplified Socraticity and that was a philosopher is really a singular proposition about Socrates, or it is not. If it is not, then the haecceity approach has not given us a singular proposition about Socrates. And if it is, then that must be because there is something special about Socraticity in virtue of which propositions containing it are singular propositions about Socrates, whereas propositions containing the property of being Plato's best teacher are not. But it seems like the only feature that Socraticity could have to give it this distinction is having Socrates himself as a constituent. And in that case, it looks like Socraticity cannot exist without Socrates after all. 3.5 Paraphrasing Accepting either (i) the view that there can be singular propositions about non--‐‐existent objects, (ii) the view that there are no singular propositions at all, (iii) the singular--‐‐propositions--‐‐with--‐‐blanks view, or (iv) the view that there are unexemplified haecceities that can "stand in" for non--‐‐present, concrete objects in singular propositions about those objects would allow the Presentist to solve the problem of singular propositions about non--‐‐present objects in a more or less straightforward way.16 But as I have said, none of these strategies 16 I say "in a more or less straightforward way" partly because, as I noted above, Adams's version of the haecceity approach purports to solve the problem of singular 12 will work for me. A fifth strategy for dealing with the problem of singular propositions about non--‐‐present objects involves the technique of paraphrasing sentences that seem to be about non--‐‐present objects into purely general past--‐‐ and future--‐‐tensed sentences.17 We have already encountered this technique above, when we considered paraphrasing (1) Socrates was a philosopher as (1a) P(∃x)(x is the referent of 'Socrates' and x is a philosopher). The idea is that once Socrates ceases to be present and thereby goes out of existence, according to Presentism, (1) has the same meaning as (1a). That is, once Socrates ceases to be present, (1) ceases to express a singular proposition about Socrates. Instead, according to this line of thought, (1) begins at that point to express the general proposition expressed by (1a). This paraphrasing approach differs from the no--‐‐singular--‐‐propositions approach in that, on the paraphrasing approach, it is admitted that there are singular propositions about present objects; the claim on this approach is that once an object ceases to be present, all singular propositions about it go out of existence, so that sentences about it – like (1) in the case of Socrates – must then be understood in some other way, as suggested by (1a). The paraphrasing approach also differs from the haecceity approach in that it does not entail the existence of any controversial items such as unexemplified haecceities. But the paraphrasing approach is not without its own problems.18 Perhaps the main difficulty with this approach is that the relevant paraphrases just don't seem to have the same meanings as the originals. For example, (1) seems propositions about non--‐‐present objects for the case of past objects but not for the case of future objects. 17 Something like this strategy is tentatively suggested by Prior in "Changes in Events and Changes in Things" (see pp. 12--‐‐14). The paraphrasing strategy is explicitly endorsed by Wolterstorff in "Can Ontology Do Without Events?" (see pp. 190ff). 18 For a discussion of further problems for the paraphrasing approach, see Smith, Language and Time, pp. 162ff. 13 to be about a man, while (1a) seems to be about a name. Also, (1) has the form of a sentence that expresses a singular proposition, while (1a) has the form of a sentence that expresses a general proposition. Moreover, it seems pretty clear that (1) did not have the same meaning as (1a) back when Socrates was still present,19 and it would be strange to say that the two sentences differed in meaning at one time and then had exactly the same meaning at a later time, even though (we can assume) there were no changes in the interpretation of the relevant language between those two times.20 3.6 Indirect Relations Between Present and Non--‐‐present Objects We will return to the problem of singular propositions about non--‐‐present objects, and consider a variation on the paraphrasing strategy, below. First, however, let us consider two strategies that I want to endorse for dealing with the problem of relations between present and non--‐‐present objects. The first strategy I have in mind involves insisting that there never really are relations between objects that are not contemporaneous, but trying to accommodate our intuition that there are by appealing to various other truths that are "in the ballpark." The strategy will also involve pointing out that the fact that there cannot be direct relations between two objects at a time when one of those objects is not present, and hence does not exist, is an instance of a more general phenomenon. The more general phenomenon occurs whenever we are inclined to say that two things stand in some relation to one another even though they do not both exist. For example, we are inclined to say that Chelsea Clinton stands in the sibling relation to her possible brother, who does not exist.21 Since there really 19 Let's pretend, for simplicity's sake, that English existed in its present form back then. For arguments that seem to show that (1) did not have the same meaning as (1a) back when Socrates was present, see Kripke, Naming and Necessity. 20 I'm grateful to Greg Fitch for making this point in correspondence. 21 For the remainder of this paper I will be assuming that Actualism is true, i.e., that there are no non--‐‐actual objects. This is because I am offering a defense of Presentism, and Presentists tend to be Actualists as well. (In fact, I do not know of a single Presentist who is not also an Actualist.) But all of the points I make based on this assumption could be made – although in a much more cumbersome way – without assuming that Actualism is true. 14 is no possible brother for Chelsea to be related to, it is not literally true that she stands in the sibling relation to any such person. But we can capture what is true about this case with a sentence in which the relevant existential quantifier lies within the scope of a modal operator, like the following (where the diamond is the modal operator standing for 'it is possible that'): (4) ◊(∃x)(x is a brother of Chelsea). Because the existential quantifier in (4) lies within the scope of a modal operator, (4) does not entail the actual existence of any possible brother of Chelsea. For this reason, (4) is acceptable even to the Actualist, who can say that although it is not literally true that Chelsea stands in the sibling relation to her possible brother, there is nevertheless a literal truth in the ballpark that we can point to in order to justify our intuition that Chelsea does stand in that relation to some possible brother. Similarly, the Presentist can maintain, when we are inclined to say that a present object stands in some relation to a non--‐‐present object, as in the case of my grandfather and myself, the thing we are inclined to say is not literally true. But in such a case, the Presentist can maintain, there is nevertheless a general truth in the ballpark that is literally true, and that we can point to in justifying our intuition. In the case of my grandfather we can express this general truth with a sentence in which the relevant existential quantifier lies within the scope of a tense operator, like (5) below. (5) P(∃x)(x is the grandfather of Ned). A similar technique will work even in a case in which the two objects in question never existed at the same time. For example, when we are inclined to say that I stand in the great--‐‐great--‐‐grandson of relation to my great--‐‐great--‐‐ grandfather, the Presentist can appeal to the following sentence, which is literally true: (6) P(∃x)[x is the grandfather of Ned and P(∃y)(y is the grandfather of x)].22 22 There is a further assumption that is required for this approach to work. It is the assumption that in every case in which there is some truth to the claim that a certain 15 The matter is more complicated in the case of causal relations among entities that are never contemporaneous, but I see no reason not to think that the same basic strategy will work even in such cases. Here is a very brief sketch of one way in which the indirect relations approach could be applied to the case of causal relations among non--‐‐contemporaneous events. It is natural to think that events generally take some time to occur, and also that direct causal relations between events always involve events that are contemporaneous for at least some period of time. If we grant these assumptions, then it will turn out that whenever we want to say that one event, e1, causes another, much later event, e23, there will be a causal chain of linking events connecting e1 and e23, such that each adjacent pair of events in the chain will be contemporaneous for at least some period of time.23 3.7 Similarities Between Time and Modality; Differences Between Time and Space Some may feel that this approach still leaves something to be desired, however, since it remains true, even according to the Presentist who takes this present object stands in some relation to a putative non--‐‐present object, there will be sufficient "linking objects" that will connect the present object to the putative non--‐‐ present object, the way my grandfather links me to my great--‐‐great--‐‐grandfather. I am inclined to accept this assumption, although I won't attempt to defend it here. 23 A great deal more space than I have here would be required to do justice to the causal version of the problem of relations between non--‐‐contemporaneous entities. For more extended discussions of the problem, see Bigelow, "Presentism and Properties"; Lucretius, On the Nature of the Universe; Sextus Empiricus, Against the Physicists; Sider, Four--‐‐Dimensionalism; the writings of the Stoics in Long and Sedley, The Hellenistic Philosophers, Volume 1, Translations of the Principal Sources with Philosophical Commentary; Tooley, Time, Tense, and Causation; and Zimmerman, "Chisholm and the Essences of Events". It is worth noting that at least some Presentists are reductionists about events, insisting that all talk that appears to be about events is really talk about things. (See, for example, Prior, "Changes in Events and Changes in Things".) Such Presentists will perhaps have an easier time than others of dealing with the problem of causal relations between non--‐‐contemporaneous events, since, for them, the problem will turn out more or less straightforwardly to be just a special case of the general problem of relations between present and non--‐‐present objects. 16 line, that there is still no direct relation between me and my grandfather. Also, it looks like the type of account exemplified by (6) won't work when we want to say that I stand in the admires relation to Socrates. This is where the second strategy that I want to endorse for dealing with the problem of relations between present and non--‐‐present objects comes in. The second strategy involves emphasizing fundamental similarities between time and modality while at the same time emphasizing fundamental differences between time and space. The claim that putative objects like Socrates, my grandfather, and my future grandchildren do not really exist, and can neither feature in singular propositions nor stand in direct relations to existing objects, is much less counterintuitive on the assumption that time is fundamentally like modality and fundamentally unlike the dimensions of space. But it can be plausibly argued that this is in fact the case. In fact, Prior and others have argued for the first part of this claim (time's fundamental similarity to modality);24 and Prior, myself, and others have argued for the second part (time's fundamental dissimilarity to the dimensions of space).25 Thus, 24 See Prior, "The Notion of the Present"; Prior, Time and Modality; Prior and Fine, Worlds, Times and Selves; Fine, "Prior on the Construction of Possible Worlds and Instants"; and Zalta, "On the Structural Similarities Between Worlds and Times". One of the main similarities between time and modality has to do with the similarities between modal logic and tense logic, and, in particular, the way the tense operators function just like modal operators. Another main similarity between time and modality involves similarities between worlds (construed as abstract objects) and times (construed as abstract objects). A third similarity between time and modality, at least according to the Presentist, has to do with ontology, and the fact that the past and the future are as unreal as the merely possible. 25 See Prior, Past, Present, and Future; Prior, "Thank Goodness That's Over"; Prior, Time and Modality; Markosian, "On Language and the Passage of Time"; Markosian, "How Fast Does Time Pass?"; Markosian, "The 3D/4D Controversy and Non--‐‐present Objects"; and Markosian, "What Are Physical Objects?". Here are some of the main ways in which it is claimed that time us unlike the dimensions of space: (1) Propositions have truth--‐‐values at times, and a single proposition can have different truth--‐‐values at different times, but the corresponding things are not true about space. (2) The so--‐‐called "A--‐‐properties" (putative properties like pastness, presentness, and futurity) are genuine, monadic properties that cannot be analyzed purely in terms of "B--‐‐relations" (binary, temporal relations such as earlier--‐‐than and simultaneous--‐‐with), but there are no genuine spatial properties analogous to the A--‐‐properties. (3) Time 17 according to this line of thought, putative non--‐‐present objects like Socrates and the others have more in common with putative non--‐‐actual objects like Santa Claus than they have in common with objects that are located elsewhere in space, like Alpha Centauri. It's very plausible to say that, although Alpha Centauri is located far away from us in space, it is no less real because of that. And similarly, it is very plausible to say that Santa Claus is less real in virtue of being non--‐‐actual. The question, then, is whether putative non--‐‐present objects like Socrates are in the same boat as Alpha Centauri in this regard or, instead, in the same boat as Santa Claus. And once it is accepted that time is fundamentally similar to modality, and fundamentally different from space, then the natural answer to this question is that Socrates is in the same boat as Santa Claus. Someone might object at this point by saying something like the following. "You're overlooking an important fact about Socrates: he was once real. For that reason, it is a big mistake to lump him together with Santa Claus, who never was real and never will be real. Socrates ought to be in the same boat as Alpha Centauri, not in the same boat as Santa Claus." My reply to this objection is that it misses the point about the fundamental similarity between time and modality and the fundamental difference between time and space. Given the fundamental similarity between time and modality, being formerly real is analogous to being possibly real. And given the fundamental difference between time and space, there is no reason to think that being real at a remote temporal location is analogous to being real at a remote spatial location. So although I admit that it might seem a little counterintuitive, I think it is actually a desirable consequence of Presentism that I cannot now stand in any direct relations to Socrates, or my grandfather, or any other non--‐‐present object, just as I cannot stand in any direct relations to Santa Claus, or my possible sister, or any other non--‐‐actual object. What about admiring Socrates, then? The problem, it will be recalled, is that it would be natural to say that I stand in the admires relation to Socrates, but according to Presentism I cannot do so, since Socrates does not now exist. What I want to say in response to this problem is that there is an exactly analogous problem with non--‐‐actual objects, and that the solution to the modal case will also work for the temporal case. passes – that is, times and events are constantly and inexorably changing from being future to being present and then on to being more and more remotely past – but nothing analogous is true of any dimension of space. 18 Consider Sherlock Holmes, for example. I admire him too, almost as much as I admire Socrates. Or anyway, I am inclined, when speaking loosely, to say that I admire Sherlock Holmes. But of course I can't really stand in the admires relation to Sherlock Holmes if, as I am assuming, Actualism is true and Sherlock Holmes doesn't really exist.26 What truth is there, then, in the intuitive idea that I admire Sherlock Holmes? Surely the correct answer will involve an analysis roughly along these lines: (7) There are various properties, p1--‐‐pn, such that (i) I associate p1--‐‐pn with the name 'Sherlock Holmes', and (ii) thoughts of either p1--‐‐pn or the name 'Sherlock Holmes' evoke in me the characteristic feeling of admiration. Note that (7) can be true even though it's also true that when the characteristic feeling of admiration is evoked in me by the relevant thoughts, the feeling is not directed at any particular object. Thus (7) captures what is true in the claim that I admire Sherlock Holmes, without requiring that there actually be such a person as Sherlock Holmes. Note also that (7) is consistent with the truth of this claim: (7a) There are various properties, p1--‐‐pn, such that (i) I associate p1--‐‐pn with the name 'Sherlock Holmes', (ii) thoughts of either p1--‐‐pn or the name 'Sherlock Holmes' evoke in me the characteristic feeling of admiration, and (iii) according to the Conan Doyle story, (∃x)(x has p1--‐‐pn and x is the referent of 'Sherlock Holmes'). Thus, it can be true that (loosely speaking) I admire Sherlock Holmes, and also true that my admiration is connected with the actual story. 26 This is perhaps an oversimplification. Some people would say that Actualism is true and that Sherlock Holmes does really exist. For some people believe that fictional characters are abstract, actual objects (like sets of properties). See, for example, van Inwagen, "Creatures of Fiction"; Howell, "Fictional Objects: How They Are and How They Aren't"; Emt, "On the Nature of Fictional Entities"; Levinson, "Making Believe"; and Salmon, "Nonexistence". For the sake of simplicity, I will ignore this point in what follows. 19 If this is right, then we can say a similar thing about my admiration of Socrates, namely, (8) There are various properties, p1--‐‐pn, such that (i) I associate p1--‐‐pn with the name 'Socrates', and (ii) thoughts of either p1--‐‐pn or the name 'Socrates' evoke in me the characteristic feeling of admiration. And (8), like (7), can be true even though it's also true that when the characteristic feeling of admiration is evoked in me by the relevant thoughts, the feeling is not directed at any particular object. Thus (8) captures what is true in the claim that I admire Socrates, without requiring that there presently be such a person as Socrates. Now, (8) is consistent with the truth of this additional claim: (8a) There are various properties, p1--‐‐pn, such that (i) I associate p1--‐‐pn with the name 'Socrates', (ii) thoughts of either p1--‐‐pn or the name 'Socrates' evoke in me the characteristic feeling of admiration, and (iii) P(∃x)(x has p1--‐‐pn and x is the referent of 'Socrates'). Thus, it can be true that (loosely speaking) I admire Socrates, and also true that my admiration is connected with the actual course of history in such a way that I am indirectly related to Socrates.27 Time's alleged similarity with modality and alleged dissimilarity with space are relevant here. For the plausibility of (8) as an analysis of what is correct about the intuitive idea that I am an admirer of Socrates depends on the claim that the case of Socrates is similar to the case of a non--‐‐actual object like Sherlock Holmes, and not similar to a case involving someone who is (temporally) present but very far away. 27 I mentioned (in note 22 above) that the indirect relations strategy is based on the assumption that there will in general be sufficient "linking objects" to generate the requisite truths. Notice that in the case of the truth about my admiring Socrates that is captured by sentence (8a), it is the name and the properties in question that do the linking. 20 Here is a related point. As a way of developing the objection to Presentism involving Glaucon and the sudden change in his beliefs when Socrates ceased to be present, the Non--‐‐presentist might say something like the following. Consider the time right before Socrates suddenly ceased to be present and the time right after. And consider the states Glaucon was in at these two times. If you just look at Glaucon, there is virtually no difference between how he is at the first of these times and how he is at the second (since we are assuming that Glaucon did not change in any important intrinsic way when Socrates ceased to be present). How is it possible, then, that there is such a big difference between Glaucon before Socrates ceased to be present and Glaucon after Socrates ceased to be present? How is it possible that the earlier Glaucon believes the singular proposition that Socrates is a philosopher and the later Glaucon does not believe that proposition, when the two Glaucons are so similar? And here is my reply to this objection. Imagine someone arguing as follows. Consider two possible worlds: the actual world, in which George W. Bush really exists, and a merely possible world – call it "w1" – in which some very powerful being is playing an elaborate trick on all of us by making it seem as if there is a man named "George W. Bush" when in fact there is not. Let the two versions of me in the two worlds have exactly the same intrinsic properties, and let my experiences in the two worlds be exactly alike, so that whenever I experience a television image of Bush in the actual world, I experience a qualitatively identical television image of (what appears to be) Bush in w1. Now, if you just look at my intrinsic properties, there is no difference between how I am in the actual world and how I am in w1. How is it possible, then, that there is such a big difference between me in the actual world and me in w1? How is it possible that the actual me believes the singular proposition that Bush is president and the me in w1 does not believe that proposition, when the two mes are so similar? The correct response to someone who argues like this would be that the me in w1 cannot believe any singular proposition about Bush for the simple 21 reason that Bush does not exist in that world. No object, no singular proposition; and no singular proposition, no belief in that singular proposition. That's how there can be such a big difference between the two versions of me even though they are so similar. And, I am suggesting, it is the same with poor Glaucon and the time after Socrates has ceased to be present. He cannot believe any singular proposition about Socrates at that time for the simple reason that Socrates does not exist at that time. No object, no singular proposition; and no singular proposition, no belief in that singular proposition. That's how there can be such a big difference between Glaucon before Socrates has passed out of existence and Glaucon after Socrates has passed out of existence.28 3.8 A Variation on the Paraphrasing Strategy Emphasizing the similarities between time and modality can also help the Presentist to deal with the problem of singular propositions about non--‐‐ present objects by employing a variation on the paraphrasing strategy discussed above. Recall that, on that strategy, the claim was that (1) Socrates was a philosopher now has the same meaning as (1a) P(∃x)(x is the referent of 'Socrates' and x is a philosopher). This approach was rejected because, upon reflection, it seems pretty clear that (1) and (1a) do not really have the same meaning at all. 28 It is worth mentioning here that the Presentist line I am defending on beliefs about non--‐‐present objects commits me to at least one version of "externalism" about beliefs, namely, the thesis that which propositions one believes is not determined solely by one's intrinsic properties but, rather, is partly determined by features of the external world, such as whether there is an object for the relevant belief to be about. This is what makes it possible for Glaucon to go from believing various singular propositions about Socrates to not believing any such propositions, even though he doesn't change in any intrinsic way. (I am grateful to Ted Sider for making this point in correspondence.) 22 But now consider the case of the two worlds discussed in the above example: the actual world, in which George W. Bush exists, and w1, in which a very powerful being is playing a trick on all of us by making it seem as if there is a guy named "George W. Bush" when there really is no such person. We surely don't want to say that in w1 the sentence (9) George W. Bush is president of the US expresses a singular proposition about Bush, even though (9) does have the form of a sentence that expresses a singular proposition about a man named "George W. Bush". And the reason we don't want to say that (9) expresses a singular proposition in w1 is that there is no such man in that world, so that there can be no such singular proposition there. But this doesn't mean that we have to say that (9) is utterly meaningless in w1. The way to say that (9) has some meaning in w1, even though it doesn't there express a singular proposition about Bush, is to distinguish between two different kinds of meaning that a declarative sentence can have. One type of meaning that a declarative sentence can have is simply the proposition (if any) expressed by that sentence. Let's call this the propositional content of the sentence.29 Sentence (9) has no propositional content in w1.30 But another type of meaning that a declarative sentence can have is the meaning associated with the truth and falsity conditions for the sentence. I'll follow Greg Fitch in calling this the linguistic meaning of the sentence.31 29 The propositional content of a sentence is, strictly speaking, a feature of individual tokens of the sentence rather than the sentence type itself (since it is, strictly speaking, sentence tokens that express propositions, rather than sentence types). But I will for the most part talk loosely here, as if propositional content were somehow a feature of sentence types. 30 I.e., tokens of (9) that occur in w1 do not express any proposition. This claim is consistent with the claim that tokens of (9) in the actual world do express a (singular) proposition, and also with the claim that tokens in the actual world of this sentence, (9a) In w1, George W. Bush is president of the US, express a (false, singular) proposition. (Since, after all, George W. Bush does exist in the actual world, and so does the proposition that he is president of the US in w1.) 31 See Fitch, "Non Denoting". As I see it, linguistic meaning will be primarily a feature of sentence types (although it also makes sense to ascribe to a sentence token 23 Acknowledging the distinction between the propositional content and the linguistic meaning of a sentence allows us to say that although (9) has no propositional content in w1, it nevertheless has linguistic meaning in that world. For in w1, just as in the actual world, (9) will have the following truth condition. (TC9) 'George W. Bush is president of the US' is true iff (∃x)(x is the referent of 'George W. Bush' and x is president of the US). (TC9) tells us, in effect, that if the name 'George W. Bush' picks someone out, and if that individual happens to be president of the US, then (9) is true. Otherwise, according to (TC9), the sentence is not true. In w1, then, where 'George W. Bush' fails to refer to anything, (9) fails to express a proposition, and thus has no propositional content. That's why it is not true there, and that's why (TC9) gets the correct result in this case.32 the linguistic meaning associated with its type). Thus, for example, we can say that the following sentence (type), (2) Peter van Inwagen is a philosopher, has this truth condition: (TC2) 'Peter van Inwagen is a philosopher' is true iff (∃x)(x is the referent of 'Peter van Inwagen' and x is a philosopher). But if need be, we can make it explicit that (TC2) should be understood as saying that a given token of 'Peter van Inwagen is a philosopher' is true iff (∃x)(x is the referent of the relevant occurrence 'Peter van Inwagen' and x is a philosopher). 32 But notice that (9) is not false in w1, either. For, as we have noted, (9) has no propositional content in w1. (TC9) entails that (9) is not true in w1, but it does not entail that (9) is also not false in that world. In order to guarantee that result, we will need to accept the following falsity condition for (9). (FC9) 'George W. Bush is president of the US' is false iff (∃x)(x is the referent of 'George W. Bush' and it's not the case that x is president of the US). What this shows is that the linguistic meaning of a sentence should be identified not simply with the truth condition for that sentence but, rather, with the combination of the truth and falsity conditions for the sentence. (I will sometimes gloss over this point in what follows.) 24 Notice that all of this is consistent with the denizens of w1 being utterly convinced that (9) really does express a true proposition (in their world). But since we know something important about their world that they do not know (namely, that there is no referent of 'George W. Bush' in w1), we are in a position to say, "Poor folks – they think they are expressing a true proposition when they utter (9), when really they are not. All they are doing instead is uttering a sentence with a linguistic meaning but with no propositional content; and on top of that, it's not even a sentence that happens to be true (for according to the correct truth and falsity conditions for (9), it is neither true nor false in w1)." Returning to our original sentence, (1) Socrates was a philosopher, what I want to say about its situation at the present time is analogous to what I have just said about (9) in w1. (1) currently has no propositional content, because it is "trying" to express a singular proposition about the referent of 'Socrates', and there is no such thing. But it doesn't follow that (1) is utterly meaningless. For it has a linguistic meaning. And in fact, as I will argue below, the correct truth condition for (1) is the following. (TC1g) 'Socrates was a philosopher' is true iff (∃x)[x is the referent of 'Socrates' and P(x is a philosopher)].33 At this point the Non--‐‐presentist might say, "Fine. If you're willing to outSmart us on the question of whether (1) expresses any proposition, by happily biting the bullet and denying that it does, there's nothing we can do about that. But what about the fact that the majority of English speakers will want to say that (1) happens to be true? How do you account for that fact, if, as you insist, the sentence does not express any proposition at all?" Here is my response. I agree that many English speakers will be inclined to say that (1) is true. But I think that there are three main reasons for this, all of which are consistent with the truth of Presentism. The first reason is that some English speakers are at least sometimes inclined toward Non--‐‐ presentism. Those people are likely to think (sometimes, at least) that (1) 33 The relevance of the subscript in the name '(TC1g)' will be clear shortly. 25 expresses something like a true, singular proposition about Socrates.34 They're making a mistake, but still, this explains why they think (1) is true.35 The second reason why so many English speakers are inclined to say that (1) is true is that even those of us who are confirmed Presentists sometimes prefer not to focus on the Presentism/Non--‐‐presentism dispute in our everyday lives. As a purely practical matter, it turns out that you can't be doing serious ontology all the time. But here something like Ted Sider's notion of quasi--‐‐ truth comes in handy.36 The idea is roughly this. Presentists and Non--‐‐ presentists disagree over a philosophical matter, but we don't necessarily disagree over any non--‐‐philosophical matter regarding some empirical fact about the current state of the world. In particular, we Presentists think that the current state of the world is qualitatively indiscernible from the way it would be if Non--‐‐presentism and (1) were both true. And that is good enough to make us want to assent to (1), in everyday circumstances, even if we don't really think it is literally true.37 The following technical term can be used to describe the situation. S is quasi--‐‐true =df S is not literally true, but only in virtue of certain non--‐‐empirical or philosophical facts. Now the point can be put this way: Presentists and Non--‐‐presentists alike, not to mention people who don't have a view on the Presentism/Non--‐‐presentism 34 I say "something like a true, singular proposition about Socrates" because I don't suppose that typical non--‐‐philosophers have any view about the existence of singular propositions. But in any case, to the extent that some people have Non--‐‐presentist leanings, they will think that (1) is currently true, because they will think that it satisfies the above truth condition. 35 If I became convinced that there were enough of such people, I would have to give up my claim (from Section 1) that Presentism is the view of the average person on the street. 36 See Sider, "Presentism and Ontological Commitment". What I describe in the text is a variation on Sider's actual notion of quasi--‐‐truth. 37 Similarly, we think that the current state of the world is qualitatively indiscernible from the way it would be if Non--‐‐presentism were true and 'Socrates was a plumber' were false; and that is good enough to make us want to say (when we are not obsessing about philosophical issues) that 'Socrates was a plumber' is false. 26 dispute, all assent to (1), in everyday circumstances, because we all think it is at least quasi--‐‐true. The third reason for the fact that a majority of people will want to say that (1) is true has to do with a very understandable mistake that people tend to make regarding the truth conditions for sentences like (1). The mistake involves blurring a distinction between two kinds of truth condition for sentences that combine names with certain modal operators.38 The distinction I have in mind can be illustrated by a difference between two different possible truth conditions that we could assign to (1). One truth condition we could assign to (1) is (TC1g), which we have already considered above, and which goes as follows. (TC1g) 'Socrates was a philosopher' is true iff (∃x)[x is the referent of 'Socrates' and P(x is a philosopher)]. The other truth condition we could assign to (1) is the following. (TC1s) 'Socrates was a philosopher' is true iff P(∃x)(x is the referent of 'Socrates' and x is a philosopher).39 The difference between (TC1g) and (TC1s) has to do with the scope of the past--‐‐tense operator on the righthand side of the biconditional. In (TC1g) the past--‐‐tense operator has narrow scope, while in (TC1s) it has wide scope. (TC1g) tells us, in effect, to grab the thing that is now the referent of 'Socrates', and then to go back to see whether there is some past time at which that thing is a philosopher. (TC1s), on the other hand, tells us, in effect, to go back to past times, and to search for a thing that is the referent of 'Socrates' and that is a philosopher. Thus the difference between (TC1g) and (TC1s) illustrates a 38 Following Prior and others, I am counting tense operators as a species of modal operator. 39 Technical point: In order to accommodate the possibility that Socrates was not named "Socrates" way back when, we may instead want the "searchy" truth condition for (1) (see explanation below) to say something like the following (in which 'F' is the future--‐‐tense sentential operator, short for 'it will be the case that'). (TC1s') 'Socrates was a philosopher' is true iff P(∃x)[F(x is the referent of 'Socrates') and x is a philosopher]. 27 difference between what we might call grabby truth conditions and what we might call searchy truth conditions for sentences combining names with modal operators.40 It should be clear that if we apply (TC1s) to (1), then, even assuming Presentism, (1) may well turn out to be true. For it may well be the case that there was a person who was the referent of 'Socrates' and who was a philosopher.41 But if we take (TC1g) to be the correct truth condition for (1), on the other hand, then (again assuming Presentism) (1) turns out not to be true (which means that it is either false or without a truth value). So which kind of truth condition should we apply to (1)? I think there is good evidence that, given the way such sentences are understood in English, the answer is that we should apply the grabby truth condition to (1). For consider this sentence: (16) Joe Montana was a quarterback. The current truth of (16) should depend on how things have been with the guy who is currently the referent of 'Joe Montana'. But if (16) had a searchy truth condition, such as the following, (TC16s) 'Joe Montana was a quarterback' is true iff P(∃x)(x is the referent of 'Joe Montana' and x is a quarterback). then (16) could be true now in virtue of the fact that someone else was formerly both the referent of 'Joe Montana' and a quarterback, even if our current Joe Montana never was a quarterback. And that would be the wrong result. So I think it's clear that (16) now has the following grabby truth condition. (TC16g) 'Joe Montana was a quarterback' is true iff (∃x)[x is the referent of 'Joe Montana' and P(x is a quarterback)]. 40 I am grateful to Tom Ryckman for suggesting the terms 'searchy' and 'grabby'. 41 If we take (TC1s') (see note 39 above) to be the correct truth condition for (1), then the point here is that it may well be the case that there was a person who would be the referent of later occurrences of 'Socrates', and who was a philosopher. 28 Moreover, I think that, even when (16) loses its propositional content, as a result of Montana's going out of existence, the sentence will not then suddenly come to have a different linguistic meaning. Which means that (16) will continue to have the same grabby truth condition it now has even after Montana ceases to exist. These considerations suggest that the conventions of English are such that the following two things will normally be true of any standard sentence combining a name and a past--‐‐tense operator: (i) like other sentences containing standard uses of names, that sentence will express a singular proposition about the referent of that name, if it expresses any proposition at all; and (ii) that sentence will have a grabby truth condition.42 If I am right about the second part of this claim, then (TC1g) is the correct truth condition for (1). Which means (again, assuming Presentism) that (1) is not true. But still, even if I am right about the correct truth condition for (1), it is quite natural that we sometimes think, "True," when we think of (1), for the simple reason that the difference between grabby truth conditions and searchy truth conditions is a fairly subtle difference. I mean, it's really not surprising that the average English speaker would confuse (TC1g) and (TC1s). I can barely tell them apart myself. If the reader still has doubts about my claim that (TC1g) is the correct truth condition for (1), here is a little empirical test that is easy to do. Go out and corral a typical English speaker on the street. Ask her to consider sentence (1), and to tell you whether it is true. She will most likely say, "Yes." Then ask her 42 Similar remarks apply to sentences containing names and alethic modal operators – they also are meant to express singular propositions about the things named, and they also have grabby rather than searchy truth conditions. E.g., this sentence, (17) Joe Montana might have been a plumber, expresses a singular proposition about Joe Montana, and it has the following grabby truth condition. (TC17g) 'Joe Montana might have been a plumber' is true iff (∃x)(x is the referent of 'Joe Montana' and ◊(x is a plumber)). That is, the correct truth condition for (17) tells us to grab the thing named "Joe Montana" and to check other possible worlds to see whether that thing is a plumber in any of them (rather than telling us to go to other possible worlds and search around for a thing that is both named "Joe Montana" and a plumber). 29 this question: "Do you think this sentence is true because there is a guy called 'Socrates' who was a philosopher, or do you think it is true because there was a guy called 'Socrates' who was a philosopher?" I'm willing to bet five dollars that if you can get her to take this last question seriously, she will opt for the second alternative (the one that corresponds to (TC1s)). And what I think this shows is that, even though the correct truth condition for (1) is (TC1g), the grabby truth condition, the average person on the street is likely to think (mistakenly) that the correct truth condition for (1) is something like (TC1s), the searchy truth condition. Now, I have argued above that (TC1g) rather than (TC1s) is the correct truth condition for (1). But there is always the possibility that I am wrong about this. If (TC1s) is actually the right truth condition for (1), then the explanation for our inclination to think that (1) is true is even simpler. The explanation is that we think (1) is true because it is (since, presumably, it has been the case that there is a guy called "Socrates" who is a philosopher).43 But notice that if we say that (TC1s) is the appropriate truth condition for (1) then we must say either (a) that (1) is true even though it fails to express a proposition, or else (b) that (1) expresses a general proposition, such as the one expressed by this sentence: (1a) P(∃x)(x is the referent of 'Socrates' and x is a philosopher). And I don't think either of these alternatives is at all tenable. On the strategy that I am endorsing, then, the claim is not that (1a) has the same meaning (in any sense of 'meaning') as (1). Nor am I claiming that the righthand side of (TC1g) expresses the same proposition as (1). Rather, the claim is that (1) fails to express any proposition at all, but nevertheless has the linguistic meaning that is captured by (TC1g).44 In addition, I am admitting that the majority of English speakers would be inclined to say that (1) is true, 43 Better yet (again taking into account the possibility that Socrates was not called "Socrates" in his time): If (TC1s') (see note 39 above) is the correct truth condition for (1), then the explanation for our inclination to think (1) is true is simply that it is, since, presumably, it has been the case that there is a guy who we will later call "Socrates" and who is a philosopher. 44 Together with the corresponding falsity condition. 30 but I am suggesting that there are three main reasons for this that are all consistent with Presentism: (i) some English speakers are occasional Non--‐‐ presentists; (ii) Presentists, Non--‐‐presentists, and agnostics with respect to the Presentism/Non--‐‐presentism dispute are all happy to say that (1) is true, because we all think it is at least quasi--‐‐true; and (iii) many English speakers are confused about the correct truth conditions for sentences like (1), mistakenly thinking that they are searchy truth conditions that happen to be satisfied rather than grabby truth conditions that are not satisfied. 3.9 Presentism and Special Relativity What about the argument from the Special Theory of Relativity (STR) against Presentism? In order to discuss the best Presentist response to it, let's first get clear on exactly how the argument is supposed to go. As I understand it, the argument goes something like this: The Argument from Relativity (1) STR is true. (2) STR entails that there is no such relation as absolute simultaneity. (3) If there is no such relation as absolute simultaneity, then there is no such property as absolute presentness. (4) Presentism entails that there is such a property as absolute presentness. ––––––––––––––––––––––––––––––––––– (5) Presentism is false. The rationale for premise (1) is whatever empirical evidence supports STR. The rationale for premise (2) is that STR apparently entails that the relation of simultaneity never holds between two objects or events absolutely, but, instead, only relative to a particular frame of reference. The rationale for premise (3) is that if there were such a property as absolute presentness, then whatever objects or events possessed it would be absolutely simultaneous with one another. And the rationale for premise (4) is that if Presentism allowed what is present to be a relativistic matter, then Presentism would 31 entail that what exists is a relativistic matter, which would be an unacceptable consequence.45 My response to this argument requires a small digression on a general matter concerning philosophical method. It is fashionable nowadays to give arguments from scientific theories to philosophical conclusions. I don't have a problem with this approach in general. But I think it is a seldom--‐‐observed fact that when people give arguments from scientific theories to philosophical conclusions, there is usually a good deal of philosophy built into the relevant scientific theories. I don't have a problem with this, either. Scientists, especially in areas like theoretical physics, cannot be expected to do science without sometimes appealing to philosophical principles. Still, I think it is important, when evaluating an argument from some scientific theory to a philosophical conclusion, to be aware of the fact that there is likely to be some philosophy built into the relevant scientific theory. Otherwise there is the danger of mistakenly thinking that the argument in question involves a clear--‐‐cut case of science versus philosophy. And I think it very rarely happens that we are presented with a genuine case of science versus philosophy. The reason I raise this methodological point here is that how I want to respond to The Argument from Relativity depends on how philosophically rich we understand STR to be. Does STR have enough philosophical baggage built into it to make it either literally contain or at least entail that there is no such relation as absolute simultaneity? I don't have a view about the correct answer to this question. But I do know that there are two ways of answering it (Yes and No). So let us consider two different versions of STR, which we can characterize as follows. STR+ = A philosophically robust version of STR that has enough philosophical baggage built into it to make it either literally contain or at least entail the proposition that there is no such relation as absolute simultaneity. STR--‐‐ = A philosophically austere version of STR that is empirically equivalent to STR+ but that does not have enough philosophical baggage built into it to make it 45 A similar argument from STR can be used against the A Theory of time. 32 either literally contain or even entail the proposition that there is no such relation as absolute simultaneity. Suppose we understand The Argument from Relativity to be concerned with STR+. Then I think premise (1) of the argument is false, because STR+ is false. Although I agree that there seems to be a great deal of empirical evidence supporting the theory, I think it is notable that the same empirical evidence supports STR--‐‐ equally well. And since I believe there is good a priori evidence favoring STR--‐‐ over STR+, I conclude that STR--‐‐ is true and that STR+ is false. Suppose, on the other hand, that we understand The Argument from Relativity to be concerned with STR--‐‐. Then I reject premise (2) of the argument. STR--‐‐ will entail, among other things, that while it is physically possible to determine whether two objects or events are simultaneous relative to a particular frame of reference, it is not physically possible to determine whether two objects or events are absolutely simultaneous. But this is consistent with there being such a relation as absolute simultaneity. And it is also consistent with there being such a property as absolute presentness.46 3.10 Presentism and Past and Future Times All of this is well and good, but what about the problem of non--‐‐present times? Here are two questions that are crucial to this topic: (Q1) What are times? (Q2) Are there any non--‐‐present times? And here are the answers to these questions that I want to endorse: 46 For more discussions of STR and the A Theory and/or Presentism, see Prior, "The Notion of the Present"; Putnam, "Time and Physical Geometry"; Maxwell, "Are Probabilism and Special Relativity Incompatible?", and Monton, "Presentism and Spacetime Physics". 33 (A1) Times are like worlds.47 (A2) In one sense there are many non--‐‐present times, while in another sense there are none. Here's how times are like worlds. Consider the actual world. There are really two of them. There is the abstract actual world, which is a maximal, consistent proposition.48 There are many things that are similar to the abstract actual world in being maximal, consistent propositions. Each one is a possible world. The abstract actual world is the only one of all of these possible worlds that happens to be true. And then there is the concrete actual world, which is the sum total of all actual facts.49 The concrete actual world is the only concrete world that exists, and it is what makes the abstract actual world true. The Presentist can say that it is the same with the present time. There are really two of them. There is the abstract present time, which is a maximal, consistent proposition. There are many things that are similar to the abstract present time in being maximal, consistent propositions that either will be true, are true, or have been true. Each one is a time.50 The abstract present time is the only one of all of these abstract times that happens to be true right now. And then there is the concrete present time, which is the sum total of all present facts. It is the only concrete time that exists, and it is what makes the abstract present time true. Talk about non--‐‐present times can be understood as talk about maximal, consistent propositions that have been or will be true. For 47 Cf. Prior and Fine, Worlds, Times and Selves; Fine, "Prior on the Construction of Possible Worlds and Instants"; and Zalta, "On the Structural Similarities Between Worlds and Times". 48 As before, I am assuming that Actualism is true. There are alternative "ersatzist" accounts that the Actualist can give of possible worlds. See Lewis, On the Plurality of Worlds. For our purposes it won't matter what specific account the Actualist gives. 49 I understand facts to be complex entities, each one consisting of the instantiation of some universal by some thing (in the case of a property) or things (in the case of a relation). 50 For reasons that have to do with what I will say below about the passage of time, the propositions that I am identifying with abstract times will have to be maximal, consistent, purely qualitative propositions. 34 example, the time ten years from now can be identified with the maximal, consistent proposition that will be true in ten years. It might be objected that there is an undesirable consequence of what I have just said, namely, that if history were cyclical, repeating itself every 100 years, say, then the time 100 years from now would be identical to the time 200 years from now. In general, it might be objected, the view about times I have endorsed entails that it is impossible for history to be cyclical without time's being closed.51 Here is my reply to this objection. On the view I am endorsing, 100 years from now there will be two items that deserve the name "the present time". One will be the concrete present time, i.e., the sum total of all facts then obtaining. The other will be the abstract present time, i.e., the maximal, consistent proposition that will then be true. The latter will be identical to the time 200 years from now, but the former will not.52 So all that follows from the combination of the view about times I am endorsing with the assumption that history repeats itself every 100 years is that the thing that will be the abstract present time in 100 years is identical to the thing that will be the abstract present time in 200 years. Here a small digression on the nature of possible worlds may be helpful. It is important to remember when talking about abstract possible worlds that they are not really worlds, in the robust sense of the word. They are not composed of stars and planets and flesh--‐‐and--‐‐blood beings (the way the concrete actual world is). They are not even composed of matter. They are just abstract objects that play a certain role in philosophers' talk about modality. They are ways things could be. That's why there are no two abstract possible worlds that are qualitatively identical. If w1 is a way things could be, and w2 is also a way things could be, and w2 is just like w1 in every detail, then w2 is identical to w1. 51 For a detailed discussion of the possibility of history's being cyclical while time is closed, see Newton--‐‐Smith, The Structure of Time, pp. 57--‐‐78. 52 Or at least, the view I am endorsing does not entail that, on our assumption about history's being cyclical, the concrete present time in 100 years will be identical to the concrete present time in 200 years. That's because the view does not entail that the objects existing in 100 years will be identical to their counterparts in 200 years, and, hence, the view also does not entail that the facts containing those objects as constituents will be identical. 35 Similar remarks can be made about abstract times on the view I am endorsing. It is important to remember when talking about these abstract times that they are just abstract objects that play a certain role in philosophers' talk about temporal matters. They are ways things are, or have been, or will be. That's why there are no two abstract times that are qualitatively identical. If t1 is a way things are, or have been, or will be, and t2 is also a way things are, or have been, or will be, and t2 is just like t1 in every detail, then t2 is identical to t1. For that reason I don't find the relevant consequence of my view about times to be undesirable. In fact, I find it highly desirable. Of course, it would be a strike against it if the view entailed that the concrete present time that will obtain in 100 years was identical to the concrete present time that will obtain in 200 years (on the assumption of cyclical history, that is). For in that case, the view would come with an extra commitment – namely, the impossibility of cyclical history without closed time – that some philosophers would find undesirable. But as I have said, this is in fact not a consequence of the view. Meanwhile, talk about the passage of time – the process by which times become less and less future, and then present, and then more and more past – can also be understood as talk about maximal, consistent propositions. For example, I have said that the time ten years from now can be identified with a certain maximal, consistent proposition. Call that proposition "T". T is false right now, but will be true ten years hence. In other words, the future--‐‐tensed proposition that it will be the case in ten years that T is true right now. In one year's time the future--‐‐tensed proposition that it will be the case in nine years that T will be true, and then a year later the future--‐‐tensed proposition that it will be the case in eight years that T will be true, and so on. To put the point a different way: T will go from instantiating will--‐‐be--‐‐true--‐‐in--‐‐ten--‐‐years to instantiating will--‐‐ be--‐‐true--‐‐in--‐‐nine--‐‐years and then will--‐‐be--‐‐true--‐‐in--‐‐eight--‐‐years, and so on. And the process by which T goes from instantiating will--‐‐be--‐‐true--‐‐in--‐‐ten--‐‐years to instantiating will--‐‐be--‐‐true--‐‐in--‐‐nine--‐‐years, and so on, can be identified with the process by which that time – T – becomes less and less future. In a similar way, it will eventually recede further and further into the past. Thus, what appears to be talk about a non--‐‐present time's becoming less and less future can be understood as talk about a maximal, consistent proposition's instantiating a succession of properties like will--‐‐be--‐‐true--‐‐in--‐‐ten--‐‐years. Here, then, is the sense in which there are some non--‐‐present times: there are some maximal, consistent propositions that will be true or have been true, 36 but are not presently true. (This is analogous to the sense in which there are some non--‐‐actual worlds: there are some maximal, consistent propositions that are not actually true.) And here is the sense in which there are no non--‐‐present times: there is only one concrete time, and it is the present time, i.e., the sum total of all present facts. (This is analogous to the sense in which there are no non--‐‐actual worlds: there is only one concrete world, and it is the actual world, i.e., the sum total of all actual facts.) An Actualist who is also a Presentist (such as myself) can say that the concrete actual world is identical to the concrete present time. It is the sum total of all current facts. Similarly, such a person can say that the abstract actual world is identical to the abstract present time. It is the one maximal, consistent proposition that is actually and presently true.53 53 I'm grateful to West Virginia University for a research grant that helped support the writing of an earlier draft of this paper. 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