Amazon Book Description
- Real Time II extends and evolves DH Mellor's classic exploration of the philosophy of time, "Mellor (D.H.) - Real Time".
- This new book answers such basic metaphysical questions about time as: how do past, present and future differ, how are time and space related, what is change, is time travel1 possible?
- "Mellor (D.H.) - Real Time" dominated the philosophy of time for fifteen years. Real TIme II will do the same for the next twenty.
Amazon Customer Review2
- Mellor says much in a short space, and he says it in an entertaining (though not always easy to understand) way. The first half of this book defends a token-reflexive analysis of tensed discourse against A-theoretical objections. The second half gives arguments in favor of Mellor's untensed theory of time.
- Mellor's theory is distinguished from other versions of the B-theory in that it
This makes for a very interesting picture of the world.
- treats change as the possession of incompatible non-relational properties by a single thing at different times,
- defines temporal order as the direction of causation3, and
- denies that people and objects (as opposed to events) have temporal parts.
- As interesting as the book was, I wish Mellor had spent more time in the second half trying to respond to possible objections. For example, he is committed to the view that a single object can exist fully at two distinct temporal locations and possess incompatible properties at each location. Though he discusses McTaggart at length, he does not seem to notice that this part of his theory might be open to McTaggart-like objections.
- This is a good piece of philosophy. It should interest anyone working in the philosophy of time, though one might want to look elsewhere for more sustained arguments. The book's most important contribution is probably its defense of B-theoretical semantics. If nothing else, it is a source of fascinating and original ideas.
In-Page Footnotes ("Mellor (D.H.) - Real Time II")
Footnote 2: From 2003. I presume the Author – Maxwell Goss – is this chap – Link (Defunct) – who seems to have moved on from Philosophy.
Routledge, 1998. 2006 digital reprint
"Mellor (D.H.) - Real Time II: Preface"
Source: Mellor - Real Time II, 1998, Preface
- I once hoped that this book could be a modest revision of my "Mellor (D.H.) - Real Time", first published in 1981 by Cambridge University Press. But it should always have been obvious that this was a forlorn hope. Changes in my own views and the flood of new work in the philosophy of time — see for example Oaklander and Smith (1994) — have forced me to rewrite that book almost completely. While enough of its main claims and arguments survive to justify calling this book Real Time II, this is a new and self-contained work. So to avoid distracting readers by noting changes in the body of the work, I shall, for the record, summarise the main ones here.
- In "Mellor (D.H.) - Real Time" I followed the custom of calling temporal locations like past, present and future ‘tenses’, while distinguishing them of course from the corresponding forms of English verbs. However as failure to observe this distinction still vitiates much philosophy of time, I here call these locations ‘A-times’, adapting from "McTaggart (J. McT. E.) - The Unreality of Time" (1908) the now standard distinction between his A and B series, which I explain in chapter 1 ("Mellor (D.H.) - Past, Present and Future"). For the same reason I now call my theory of time a ‘B-theory’ and my main opponents ‘A-theorists’. The terms ‘tensed’ and ‘tenseless’ I confine to their original, proper and trivial grammatical uses.
- In chapter 2 ("Mellor (D.H.) - Truths and Truthmakers") I make more explicit what all serious A- and B-theorists mean by debating the ‘truth conditions’ of beliefs about the past, present and future. A common but vacuous use of ‘truth condition’, which lets beliefs have both A- and B-truth-conditions, can easily make our debate look pointless. But it is not. For what both parties mean by a belief’s truth condition is its so-called ‘truthmaker’, i.e. what in the world makes it true. What we disagree about is whether A-facts or B-facts — in the substantial sense of ‘fact’ for which I now argue explicitly — make temporal beliefs true. This is a real issue, for if B-facts do this job, A-facts do not; and if they do not, then they do not exist, since this is what they2 exist to do.
- In "Mellor (D.H.) - Real Time" I defended the token-reflexive view that an A-proposition like ‘e is present’ is true at a B-time t if and only if a token of it — e.g. a statement of it, or someone’s belief in it — at t would be true. But Quentin Smith (1993a3 chapter 3) and others have shown that this cannot cope with propositions like ‘there are no tokens now’, which can be true even though they can have no true tokens. So in chapter 3 ("Mellor (D.H.) - Tokens and Times") I now advocate the simpler view that ‘e is present’ is made true at t by e’s being located at t, and similarly for other A-propositions.
- Chapter 4 ("Mellor (D.H.) - The Presence of Experience") contains a new response to the claim in "Prior (Arthur N.) - Thank Goodness That's over" (1959) that B-theorists cannot make sense of people thanking goodness that something, e.g. a pain, is past. My old response was shown to be inadequate by the late and sadly missed Murray Macbeath (19834), who also showed me how to correct it. Following him I now exploit the fact that whenever we thank goodness for something’s being past, what makes us do so is not that it is past but that we believe it is; so if, as I argue, we B-theorists can say in B-terms what any such A-belief is, and what makes it true, we can make as much sense as A-theorists of our gratitude for (or any other propositional attitude to) the truth of any A-proposition.
- Spatial analogues of A- and B-theories are developed in chapter 5 ("Mellor (D.H.) - Time and Space") much as in "Mellor (D.H.) - Real Time". The main addition is a short section (for which I am indebted to Sir Martin Rees) showing that modern cosmology does not, as some A-theorists suppose, undermine objections to A-theories based on the special theory of relativity. Far from yielding a privileged reference frame and hence absolute simultaneity across space, its uniform treatment of the expansion of the universe implies that there is no such thing.
- In chapter 6 ("Mellor (D.H.) - Thinking in Time") I answer an objection in David Kaplan’s (19895) to my theory that a sentence like ‘Jim races tomorrow’ means a function from any time t to its truth condition at t, namely that Jim races the day after t. Among B-theorists the issue is merely terminological — should this function or its values be called the sentence’s ‘meaning’? — but here it is more than that. For by taking it for granted that A-sentences are made true by B-facts like Jim’s racing on 2 June, rather than A-facts like Jim’s racing tomorrow, Kaplan begs the question against A-theorists, as I do not.
- To my development and defence of McTaggart’s argument against A-facts in chapter 7 ("Mellor (D.H.) - McTaggart's Proof") I have added a rebuttal of Michael Tooley’s (1997) new theory of time. This admits only B-facts, while denying, unlike most B-theories, that they all exist at all times (on the grounds that B-facts about an event e come to exist only when e does), so that the universe of facts grows over time. This I argue, besides contradicting relativity (as Tooley admits), can appeal only if we confuse e’s being located at t with its existing at t. Even if the former is what makes ‘e exists at t’ true, e’s existence at t will still make both ‘e exists’ and ‘e exists at t’ true at all times.
- The B-theory of change in chapter 8 ("Mellor (D.H.) - Change") differs in one major way from that given in "Mellor (D.H.) - Real Time". There I argued that any changeable property F (e.g. a temperature) of a thing a is a relation a has to any B-moment t when it is F.
- I am now persuaded that this is wrong. However, I still reject the orthodox B-alternative that F is a property of a temporal part of a, namely a-at-t, since I still deny that things, as opposed to events, have temporal parts in any serious sense. I argue instead that a’s being F at any t is a B-fact whose only constituents are a and F — the time t being not a constituent of this fact but merely its temporal location. This, by making F what it seems to be, a non-relational property of a itself, stops changes in a reducing either to a’s being differently related to different times or to different temporal parts of a having different properties. That in turn shows why change, so understood, has no spatial counterpart, thus making time as much the dimension of change on my B-theory as it is on any A-theory.
- In "Mellor (D.H.) - Real Time" I took Davidson’s ("Davidson (Donald) - Causal Relations") view of causation6 as a relation between particular events. Now, for reasons given in my The Facts of Causation7 (1995 chapter 9) and summarised here in chapter 9 ("Mellor (D.H.) - Events, Facts and Causation"), I think causation8, if it relates anything, relates facts, like the fact at t that a is F. This simplifies my B-theory of the relation between causation9 and time, notably by putting the causation10 of stasis — a’s being F at a later t’ because it is F at t — on a par with that of change. It does however require a parallel treatment of the earlier—later relation, as holding between facts rather than between events or times. This is argued for in chapter 10.4 ("Mellor (D.H.) - Causation and Time"), where I infer on the one hand that events cannot be spacetime points or regions, and on the other, with Leibniz (1717), that it makes no sense to imagine everything happening ten minutes later, say, than it actually does.
- The main argument of chapter 10 ("Mellor (D.H.) - Causation and Time")is that causation11 is what distinguishes time from space and gives it its direction; in short, that time is the causal dimension of spacetime. Much of this argument follows "Mellor (D.H.) - Real Time", but there are three important additions. In §3 I dispose of apparent cases of simultaneous causation12. In §5 I show how time’s being the dimension of causation13 makes it also what Kant ("Kant (Immanuel), Kemp Smith (Norman) - Immanuel Kant's Critique of Pure Reason", B50) calls ‘the form of inner sense’. (This supersedes a related but weaker argument in "Mellor (D.H.) - Real Time".) And in §6, influenced by Robin Le Poidevin (1991 chapters 5-8), 1 show why the need for causation14 to preserve the identity of a thing through changes in its properties restricts change to the causal dimension of spacetime.
- In chapter 11 ("Mellor (D.H.) - The Direction of Time") I amplify my rebuttal in "Mellor (D.H.) - Real Time" of the still widely-held view that it is not causation15 but irreversible processes which give substance to the difference between earlier and later and thus give time its direction. I also simplify my causal explanation of our experience of the direction of time (as an accumulation of memories, of memories of memories, and so on) and my demystification of forward time travel16.
- The case in chapter 12 ("Mellor (D.H.) - The Linearity of Time") against causal and hence timelike loops differs from that in "Mellor (D.H.) - Real Time". There it derived from Michael Dummett’s ("Dummett (Michael) - Bringing About the Past", 1964) argument against backward causation17. I have now replaced that argument’s epistemic assumptions with the assumption, argued for in chapter 2 of The Facts of Causation18, that effects have chances, with and without their causes, which are real possibilities of their occurring in the relevant circumstances. (Thus for Jim’s smoking, C, to cause him to get cancer, E, his metabolism must give him chances of getting cancer both if he does and if he does not smoke.) I also argue for my previously tacit assumption that, as all agree, a causal relation has only two terms. This requires the fact that C causes E, and so E’s chances with and without C, to be logically independent of C’s causes, and so in particular of C’s chances with and without E. But I show that, if there were causal loops, these chances would not be independent; so there can be no such loops, and therefore neither backward causation19 nor circular time. This, on my reading of chances as real possibilities, validates the old but much-maligned objection to backward time travel20: namely, that if Dr Who, say, could travel into his past he could kill his grandmother in her infancy and so make his trip impossible, which is absurd. And so it is.
- I owe much to many people for ideas and arguments about time and related matters that have influenced the contents of this book. Relevant work in English published after "Mellor (D.H.) - Real Time" is included in the Bibliography. Besides those mentioned above, I am especially indebted21 to the work and comments of L. Nathan Oaklander, and also to Alexander Bird, Jeremy Butterfield, M.J. Cresswell, Kenneth Denbigh, Heather Dyke (And see also22?), John Earman, David Farmer, Jan Faye, William Grey (formerly William Godfrey-Smith), Katherine Hawley, Mark Hinchliffe, Ian Hinckfuss, Arnold Koslow, John Perry, David Lewis, E.J. Lowe, J.R. Lucas, G.C. Nerlich, Eric Olson, L.A. Paul, Huw Price, Graham Priest, H. Reichenbach, Peter J. Riggs, Gonzalo Rodriguez-Pereyra, David H. Sanford, Kieran Setiya, Lawrence Sklar, J.C.C. Smart, J.W. Smith, Paul Teller, Michael Tooley, Susan Weir and J.T. Whyte.
- Finally, … [snip] …
→ Cambridge March 1998
In-Page Footnotes ("Mellor (D.H.) - Real Time II: Preface")
Footnote 1: Explains the changes since "Mellor (D.H.) - Real Time".
Footnote 2: Is this conditional referring to A-facts or B-facts? Or is it rhetorically referring to either, whichever should be correct? Mellor, at any rate, claims that so-called A-facts – ie. past, present and future – do not exist.
Footnote 3: Sadly, I don’t have this, or other papers mentioned but not explicitly referenced by links within my website. What I do have by these authors is indicated in the links from the acknowledgement list Mellor gives at the end of this Preface, except when they are not mentioned there, when they appear in footnotes like this with a link like this – Quentin Smith.
Footnote 4: Sadly, I don’t have this paper. See Murray MacBeath.
Footnote 5: Sadly, I don’t have this paper. See David Kaplan.
Footnote 21: A similar list appeared in "Mellor (D.H.) - Real Time: Introduction and Summary".
Footnote 22: And also Heather Morland-Dyke?
"Mellor (D.H.) - Real Time II: Introduction"
Source: Mellor - Real Time II, 1998, Introduction
- What follows below is the full text of the Introduction. I have divided it into the two sections – Preamble and Summary.
- I have also added the occasional footnote1 of my own, and added links to whatever I have by the authors mentioned.
- It is also worth referring to:-
in order to see how Mellor’s thoughts have developed between the two versions of the book.
- "Mellor (D.H.) - Real Time: Introduction and Summary", in
- "Mellor (D.H.) - Real Time", as well as
- "Mellor (D.H.) - Real Time II: Preface" in this book ("Mellor (D.H.) - Real Time II")
Preamble (Full Text)
- Like its ancestor, "Mellor (D.H.) - Real Time", this book is about such of the metaphysics of time as follows from settling the basis in reality of our distinctions between past, present and future. One way and another that covers most of time’s metaphysics, including the following questions2:-
All these questions will be answered in the course of settling the status of past, present and future.
- What makes a statement that something is past, present or future true or false?
- What is it to have the thoughts that such statements express, and why do we have them?
- How do we know when they are true: what tells us whether something is past, present or future?
- Why do we only ever act and have experiences in the present, affect what is future and see what is present or past?
- Could there be exceptions to this: could a time machine3 let us see the future or affect the past?
- What, even in time machines4, makes everything outside us keep moving from our future to our past via our present, i.e. what makes time flow?
- What has the flow of time to do with change, why has it no spatial analogue, and what does this fact tell us about how time differs from space?
- There are of course other metaphysical questions about time, and three5 of them at least I shall not try to answer.
These questions are too independent of those I shall discuss, and too large, to be tackled here. (The last turns too much on cosmology, the second on how far the measurement of time depends on conventions, and the first on the logic of infinity.)
- Is time continuous, dense or discrete?
- What makes time intervals differ or be the same in extent?
- Has time a beginning or an end?
- On the questions I shall discuss I noted in my 1981 "Mellor (D.H.) - Real Time: Introduction and Summary" that the literature was then so vast and various that I could not do it justice succinctly without obscuring the argument I wished to present. The situation has not changed. If anything, the flow of philosophical works on time, if not of time itself, has grown since then. In writing this book I have taken account of it, and of my own changing views, in the ways indicated in "Mellor (D.H.) - Real Time II: Preface". But it is no more feasible now than it was then to discuss all the works on time and related matters that I have read and been affected by. So now as then I hope that the fewness of my references will not be taken as a sign of ignorance or arrogance. On the contrary, it means that I take my main points, if disputed, to be so common in the literature as to be by now public property. So as before I trust that no offence will be taken by, or on behalf of, those whose well-known work I adopt, adapt or reject without explicit acknowledgement.
- This book in short is not a guide to the philosophical literature on time. Like "Mellor (D.H.) - Real Time", it is a self-contained, argued exposition of a theory of time many of whose points are already familiar to philosophers. As before, its aim is simply to develop and defend the theory in plain terms and to show how ramified its consequences are. There if anywhere lies its claim to be read. So, to fortify that claim, I will now sketch the main points I wish to make, in case they are obscured by the detail of ensuing chapters.
Summary (Full Text)
- My answers to the main questions I tackle are as follows. There is in reality no such thing as being past, present or future. By this I do not mean that it is never true to call an event e past, present or future: that would be absurd. The question is, what makes a statement like ‘e is past’ true when it is true, namely at any time later than e? There are two answers to this question. One is that at any such time e has the property of being past. This is what, in "McTaggart (J. McT. E.) - The Unreality of Time" (1908) now standard terminology, I call the ‘A-theory’ view. My own ‘B-theory’ view is that what makes ‘e is past’ true at any time t is the fact that e is earlier than t. Similarly, what makes ‘e is present’ true at any t is e’s being located at t, and what makes ‘e is future’ true at any t is e’s being later than t.
- This B-theory entails that there are no such A-properties as being past, present or future, since e’s being past, present or future at t is by definition what makes ‘e is past’, ‘e is present’ or ‘e is future’ true at t. So if, as the B-theory says, that is not what makes these A-statements true, these A-properties do not exist. Compare for example ‘Nobody is smaller than a flea’. What makes this true is not that there is such a person as Nobody, who is smaller than a flea, but that no person is that small. So there is no such person as Nobody, since if there were all true instances of ‘Nobody is F’ would by definition be made true by Nobody’s being F. As that is not what makes any such statement true, there is no such person.
- But why is no true ‘Nobody is F’ made true by something’s — Nobody’s — being F? The reason is that to make all such statements true Nobody would need impossible combinations of properties. Not only for example would Nobody have to be smaller than a flea, he and she (Nobody is both male and female …) would also have to be larger than a galaxy6. But as nothing can be both smaller than a flea and larger than a galaxy, there can be no such person. So every true ‘Nobody is F’ must be made true, as it obviously is, by something else, namely the fact that no person is F.
- Similarly7, if less obviously, with ‘e is past’, ‘e is present’ and ‘e is future’. These A-statements cannot consistently be made true when they are true by e’s having the A-properties of being past, present and future — or so McTaggart argued. I agree with him, and will defend and update his proof of this in chapter 7 ("Mellor (D.H.) - McTaggart's Proof"). This is why I say that there are no A-properties, and that our A-statements need other truthmakers. And then it is obvious what their truthmakers are, namely those given above by the B-theory.
- Unfortunately not everyone accepts McTaggart’s proof. So to win the day as well as the argument we B-theorists must press other objections to A-theories of time. One is that important consequences drawn by many A-theorists from events being past, present or future conflict with modern cosmology, which makes simultaneity at a distance relative to an arbitrary choice of so-called ‘reference frame’. For a star like Sirius, about ten light-years away, this means that no frame-independent fact fixes which Sirian events within a twenty8 year span are simultaneous with your reading of this sentence and therefore present. This poses no problem for those A- and B-theorists who think it is always true to say of any actual event, whenever it occurs, that it exists9. But most A-theorists (and some B-theorists10) say that nothing exists until it is present11, and for them, modern cosmology poses a real problem, since no one can seriously take existence12 to be relative to an arbitrary choice of reference frame.
- Besides pressing objections to A-theorists, we B-theorists must dispose of their objections to us. One, dealt with in13 "Mellor (D.H.) - Real Time", is that A-statements cannot be translated by B-statements. Thus ‘e is past’, said at t, cannot mean14 that e is earlier than t. For if ‘e is earlier than t’ is ever true it is always true, while ‘e is past’ is true only after e; and obviously no two statements can be synonymous if one can be true when the other is false. But this does not stop the fact that e is earlier than t making ‘e is past’ true at t. Compare for example ‘I live in Cambridge’ said by any person x (where ‘x’ is a name like ‘Hugh Mellor’, not like ‘me’). This cannot mean that x lives in Cambridge, for if ‘x lives in Cambridge’ is true, it is true whoever15 says it, whereas ‘I live in Cambridge’ is only true if said by a Cambridge resident. Yet16 no one can deny that the truthmaker for ‘I live in Cambridge’, said by any x, is that x lives in Cambridge.
- We B-theorists need not then make the hopeless claim that A-statements are translatable by B-statements. Yet despite this we can still say in B-theory terms what A-statements mean. For all I need to know in order to understand and use the sentence ‘e is past’ is that it is true at any time t if and only if t is later than e. Similarly, all I need to know to understand and use ‘I live in Cambridge’ is that this is true if and only if a resident of Cambridge says it. So on the orthodox view of a sentence’s meaning, as what we must know in order to be able to understand and use it, what ‘I live in Cambridge’ means is a function, from any person x to its truth-maker if said by x, namely that x lives in Cambridge. Similarly, I say, what the A-sentence ‘e is past’ means is a function from any B-time t to its B-truthmaker at t, namely that t is later than e; and similarly for ‘e is present’ and ‘e is future’.
- This kind of B-theory, giving a semantics as well as a metaphysics for A-statements, has been called ‘the new theory of time’, to distinguish it from older17 B-theories that try to translate or dispense with A-statements. My B-theory does neither. For not only, as we have seen, does it show why A-statements are untranslatable, it also shows why we need the A-beliefs these statements express. The reason is that we need such beliefs to make us act successfully when our success depends, as it nearly always does, on our acting only at certain times. I know for example that it is no use shopping when the shops are shut. So I shop only when, and because, I believe they are open, i.e. open now. If this A-belief of mine is true, I will succeed in shopping, and if it is false I will fail. This is a quite general link between belief and truth: truth is that property of beliefs which makes the actions18 they combine with our desires to cause succeed, i.e. achieve the objects of those desires. So if an action’s success depends on when it is done, its causes must include a belief which is not always true and which we therefore try to have only when it is true. But as we have seen, being true only at certain times is the mark of an A-belief, since all B-beliefs that are true at all are true always.
- This is why no agent, human or animal, that acts on its beliefs, and must act at certain times to get what it wants, can do without A-beliefs. But then we agents must be constantly changing our A-beliefs, especially our beliefs about what is happening now, in order to try to keep them true. These changes in us, mostly prompted by our senses, are what make us think of time as flowing, even though it does not flow. For without such properties as being past, present and future, time cannot flow, i.e. make events change from being future to being present and then to being past. But time need not flow for things to change in other ways, by having other incompatible properties, like different temperatures, at different times. And that includes me changing my A-belief that e is future successively for the incompatible A-beliefs that e is present and that e is past. This sequence of A-beliefs is a real process of change — but only in me19, not in e. Changes like this are the psychological reality behind the A-theorist’s myth20 of the flow of time.
- This is why our undeniable experience of time flowing is no evidence that time really does flow. Nor does the undeniable fact that all our actions and experiences occur in the present support the A-theory. For on a B-theory it is true by definition to say, at any time t, of anything at t, that it is present. So in particular it is always true to say or think, whenever we do or experience anything, that this action or experience of ours is present. The confining of all our actions and experiences to the present is not a real constraint on their location but a mere tautology21, like my inability to be anyone but me or anywhere but here.
- This account of the presence of experience also explains how we can tell whether an event is past, present or future. No B-theory can admit that these non-existent properties of events are perceptible, and indeed they are not. We cannot for example refute someone who claims to see the future in a crystal ball by pointing to the visible pastness of the scene it shows, since there is no such thing. Whether it is past or future, the scene will look the same. Nor can the look of a supernova tell us directly how long ago it happened. That we must infer from its independently known distance and the speed of light, which tells us how much earlier it is than our experience of seeing it — and hence, since we are seeing it in the present, how past it is. Similarly with the terrestrial events which, as we see them, we take to be happening almost now, because the light we see them by takes so little time to reach us. This is what tells us that most of what we are seeing is, for all practical purposes, present.
- How can we tell when events are future? We cannot tell this by seeing them, and not just because being future is not a visible property of events. For while an event is future we cannot see it at all, since the future is by definition later than the present, seeing something (or perceiving it in any other way) is always an effect of what is seen, and causes always precede their effects. But if this link between the causal order of events and their time order stops us seeing directly that an event is future, it can enable us to tell this indirectly, as when we predict the future effects of our present actions or of the other present events that we can now see.
- The link between time and causation22 also enables B-theorists to explain why it is that, although — or rather because — we can see the past, we cannot affect it. To do so, of course, this link must be, as it is, consistent with a B-theory of time. But consistency is not enough: to be adequate, our theories of causation23 and time must between them explain why the link holds. Many philosophers explain this by using the time order of events to fix their causal order, defining a cause as the earlier of two causally related events. I do it the other way round, using an independently defined causal order to fix the time order of all events, even of those that are not related as cause to effect.
- This enables me to meet several other challenges to B-theories of time. First, it lets me distinguish time from the dimensions of space, and define its direction, not as that in which time flows but as that of causation24. For while a cause often has effects in the same place as itself, or in any spatial direction from it, this is never so in time. A causal definition25 of time order explains all this by requiring a cause’s effects to occur in the same temporal direction from it, namely later. This can then be, and I argue is, what makes time differ from space and gives substance to its direction, i.e. to the difference between being earlier than something and being later than it.
- Second, we can use the causal machinery of memory to show why the time order we perceive in the world, and in our own experiences, must generally coincide with that given by the causal order of events. By doing so I show in particular how a causal definition of time, and of time order, entails the success of Kant’s famous definition of time as ‘the form of inner sense’, i.e. as the dimension in which our own experiences are ordered.
- Third, if time is the dimension of causation26, the need for causation27 to preserve the identity of a thing as its properties change shows why, since causes and effects cannot be simultaneous, there can be no spatial analogue of change. This in turn, by explaining why only temporal and not spatial variations of properties can be changes, meets the most persistent objection to B-theories, namely that only the A-theory’s flow of time can account for the essentially temporal nature of change. That is not so: the dimension of change must also be the dimension of causation28.
- Finally, I can explain why no one can affect the past or recall the future. This might seem to follow directly from a causal definition of time order, but in fact it does not29. For the definition does not itself rule out the causal and hence temporal loops that would let us affect our past by letting us travel back in time. Suppose for example Dr Who’s time machine30 TARDIS could travel back in an hour from 2045 to 1945. Then he could recall in 1945 what he had seen and done an hour earlier in 2045, and those events could affect events in 1945, e.g. by causing a fashion for futuristic scarves of the kind he decided in 2045 to wear.
- Why can this not happen? The classic answer is that, if it could, Dr Who could, e.g. by killing his infant grandmother, cause himself never to leave in 2045 (by causing himself not to exist), thus causing a contradiction, which is impossible. Although this answer has convinced few philosophers, it is in fact correct, as I shall show in the last31 chapter. To find out why — and why I make the other claims outlined above — now read on …
COMMENT: Useful summary of the book's conclusions. Compare with "Mellor (D.H.) - Real Time: Introduction and Summary".
In-Page Footnotes ("Mellor (D.H.) - Real Time II: Introduction")
Footnote 1: Some of which may be removed or clarified if and when I read the book.
Footnote 2: This is a different set of questions to those in "Mellor (D.H.) - Real Time: Introduction and Summary".
Footnote 5: There was a 4th non-discussed question in "Mellor (D.H.) - Real Time: Introduction and Summary".
Footnote 6: Because “Nobody is larger than a galaxy”, and “Nobody” is taken to be univocal.
Footnote 7: Just what is the analogy here? Presumably “F” corresponds to “e and “Nobody” to “past” (etc.). The ordering is reversed.
Footnote 8: Why?
Footnote 9: Why is the existence of any event key here?
Footnote 10: Remember that Mellor is a B-Theorist, though presumably not of this camp?
Footnote 11: What does this mean? Just that future events do not exist, whereas present and past ones do? So, most A-theorists are supporters of the “growing block universe”? They are neither presentists nor eternalists.
Footnote 12: Agreed. This is (slightly) analogous to the “arbitrariness” – or “only a and b” – objection to “Closest Continuer theories of personal identity.
Footnote 13: Is it also dealt with in "Mellor (D.H.) - Real Time II"?
Footnote 14: Note that this is a question of meaning, not truth.
Footnote 15: Ie. Any y can say this truly of x, if x lives in Cambridge.
Footnote 16: So, the analogy with time is … ?
Footnote 17: Who propounded these, and what were they?
Footnote 18: So, this adopts the standard Belief / Desire model of Action. Does everyone (and does it matter)?
Footnote 19: While what Mellor says is true, these changes are NOT merely psychological, but – in general – responses to the external world.
Footnote 20: Can the B-theorist really not accommodate the “flow” of time?
Footnote 21: These are indexicals, but the term doesn’t seem to be used by Mellor.
Footnote 25: As in "Mellor (D.H.) - Real Time: Introduction and Summary", Mellor “defines” time – is this possible? Also, the “definition” appears to rule out – a priori – backward causation. But Mellor later says “no” – because of the “possibility” of causal or temporal loops – though backward causation is later ruled out for logical reasons – the well-known “grandfather paradox” (though Mellor uses “grandmother”).
Footnote 29: Why not?
Footnote 31: See "Mellor (D.H.) - The Linearity of Time". Why has the argument “convinced few philosophers”?
"Mellor (D.H.) - Past, Present and Future"
Source: Mellor - Real Time II, 1998, Chapter 1
- The Question About Time
- A- and B-Series
- Seeing A- and B-Times
"Mellor (D.H.) - Truths and Truthmakers"
Source: Mellor - Real Time II, 1998, Chapter 2
- A-Facts and B-Facts
- Temporal Truth-Makers
"Mellor (D.H.) - Tokens and Times"
Source: Mellor - Real Time II, 1998, Chapter 3
- 'Here Be (No) Tokens'
- Necessary Pasts and Possible Futures
- Complex A-Propositions
"Mellor (D.H.) - The Presence of Experience"
Source: Mellor - Real Time II, 1998, Chapter 4
- The A-Theory of Clocks
- 'Thank Goodness That's Over'
- The Necessary Presence of Experience
- A B-Theory of Our Times
"Mellor (D.H.) - Time and Space"
Source: Mellor - Real Time II, 1998, Chapter 5
- Spatial Analogues of Time
- A- and B-Places
- The B-Theory of A-Space
- The Difference Between Time and Space
- Relativity and the Present
"Mellor (D.H.) - Thinking in Time"
Source: Mellor - Real Time II, 1998, Chapter 6
- The Irreducibility of A-Beliefs
- A-Meanings and B-Truth-Conditions
- Actions and Beliefs
- Experiencing the Flow of Time
"Mellor (D.H.) - McTaggart's Proof"
Source: Mellor - Real Time II, 1998, Chapter 7
- Change and the Flow of Time
- The Contradiction of the Flow of Time
- In Defence of McTaggart
- McTaggart and Truth Conditions
- A Growing B-World
"Mellor (D.H.) - Change"
Source: Mellor - Real Time II, 1998, Chapter 8
- The B-Theory of Change
- Events and Things
- Changes and Properties
- Change, Difference and Identity
- Properties as Relations to Times
- The B-Facts of Change
- No Experience of the Flow of Space
"Mellor (D.H.) - Events, Facts and Causation"
Source: Mellor - Real Time II, 1998, Chapter 9
- Events as Changes
- Changes: Events or Facts?
- Causes and Effects of Changes
- The Causation1 of Stasis
- In Defence of Factual Causation2
"Mellor (D.H.) - Causation and Time"
Source: Mellor - Real Time II, 1998, Chapter 10
- Perception, Action and Time
- Causal and Temporal Order
- Simultaneous Causation1
- Ordering Facts, Events and Times
- The Causal Form of Inner Sense
- Causation2 and Change
"Mellor (D.H.) - The Direction of Time"
Source: Mellor - Real Time II, 1998, Chapter 11
- Earlier and Later
- Experiencing the Direction of Time
- Forward Time Travel1
COMMENT: Photocopy filed in "Various - Papers on Logic & Metaphysics Boxes: Vol 2 (F-N)".
"Mellor (D.H.) - The Linearity of Time"
Source: Mellor - Real Time II, 1998, Chapter 12
- Backward Time Travel1
- The Chances of Causation2
- The Logical Independence of Causal Facts
- The Impossibility of Causal Loops
Text Colour Conventions (see disclaimer)
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