The distinction between presentism and eternalism is usually sought in some formula like ‘Only presently existing things exist’ or ‘Past, present, and future events are equally real’. I argue that ambiguities in the copula prevent these slogans from distinguishing significant opposed positions. I suggest in addition that one can find a series of significant distinctions if one takes spacetime structure into account. These presentisms and eternalisms are not contradictory. They are complementary elements of a complete naturalistic philosophy of time.

J. M. E. McTaggart, in a famous argument, denied the reality of time because he thought that passage or temporal becoming was essential for the existence of time and that passage was a self-contradictory concept. This denial of passage has provoked a vast literature, two of the most important contributions being C. D. Broad’s painstaking defence of passage in his Examination of McTaggart’s Philosophy and D. C. Williams’ dazzling condemnation of it “The Myth of Passage.” -/- A careful reading of (...) these apparently opposed essays reveals that there is a common notion of passage that both philosophers endorse, the successive occurrence of sets of simultaneous events (assuming classical or Newtonian spacetime structure as background). This unexpected agreement provides a notion of the passage of time that, I claim, is lean enough to survive the criticisms of passage-deniers yet robust enough to satisfy the requirements of passage-affirmers. I undertake to describe and defend this notion. -/- . (shrink)

Mark Hinchliff concludes a recent paper, "The Puzzle of Change," with a section entitled "Is the Presentist Refuted by the Special Theory of Relativity?" His answer is "no." I respond by arguing that presentists face great difficulties in merely stating their position in Minkowski spacetime. I round up some likely candidates for the job and exhibit their deficiencies.

While experience tells us that time flows from the past to the present and into the future, a number of philosophical and physical objections exist to this commonsense view of dynamic time. In an attempt to make sense of this conundrum, philosophers and physicists are forced to confront fascinating questions, such as: Can effects precede causes? Can one travel in time? Can the expansion of the Universe or the process of measurement in quantum mechanics define a direction in time? In (...) this book, researchers from both physics and philosophy attempt to answer these issues in an interesting, yet rigorous way. This fascinating book will be of interest to physicists and philosophers of science and educated general readers interested in the direction of time. (shrink)

The aim of this essay is to introduce philosophers of science to some recent philosophical discussions of the nature and origin of the direction of time. The essay is organized around books by Hans Reichenbach, Paul Horwich, and Huw Price. I outline their major arguments and treat certain critical points in detail. I speculate at the end about the ways in which the subject may continue to develop and in which it may connect with other areas of philosophy.

ABSTRACT Kit Fine recently described and defended a novel position in the philosophy of time, fragmentalism. It is not often that a new option appears in this old field, and for that reason alone these two essays merit serious attention. I will try to present briefly but fairly some of the considerations that Fine thinks favour fragmentalism. I will also weigh the merits of fragmentalism against the view that Fine presents as its chief rival, relativism, as well as the merits (...) of both against the view that he calls anti-realism. Along the way, we should pick up a clearer picture of fragmentalism itself. (shrink)

I wish to discuss a supposed implication of one sort of time travel. The sort of time travel is time travel into one’s past along a closed timelike curve. The implication is that in spacetimes with CTCs there can be no temporal passage or “flow” of time. I will argue that the implication does not hold.

One of the questions that is addressed, from various perspectives, is the origin of time-asymmetry. Given the time-symmetry of the dynamical laws, all inferences about the future that are derivable from a dynamical theory are matched by inferences about the past. For Huw Price, who discusses the origins of cosmological time asymmetry, this is reason to treat all time-asymmetric cosmological theories with caution. He dismisses both the inflationary model and Stephen Hawking’s proposal to account for time-asymmetry with his famous “no (...) boundary condition.” Instead, on the basis of the fact that we have no a priori reasons to distinguish between initial and final conditions, he advocates Gold’s time-symmetric model for the universe, in which the thermodynamical arrow of time is tied to the expansion of the universe, so that in the contracting phase towards the big crunch, entropy decreases. (shrink)

Richard Arthur and I proposed that the present in Minkowski spacetime should be thought of as a small causal diamond. That is, given two timelike separated events p and q, with p earlier than q, they suggested that the present is the set I+ ∩ I-. Mauro Dorato presents three criticisms of this proposal. I rebut all three and then offer two more plausible criticisms of the Arthur/Savitt proposal. I argue that these criticisms also fail.

I present an account of the passage of time and the present in relativistic spacetimes, and I defend these views against recent criticism by Oliver Pooley and Craig Callender.

In a recent book, Asymmetries in Time, Paul Horwich presents a systematic account of various temporal asymmetries, including a neo-Reichenbachian account of the (apparent) fact that we know more about the past than the future, the epistemological time asymmetry. I find some obscurities in Horwich's presentation, however, and I argue that when his view is understood in a way that I shall propose, it does represent an advance on Reichenbach's, but it fails to vindicate Horwich's "main point...that our special knowledge (...) of the past derives from the fork asymmetry. (shrink)

ABSTRACT In his contribution to this issue, “A and B Theories of Closed Time”, Phil Dowe argues that A- and B-theories of time are equally compatible with closed time, though it is commonly supposed that only B-theories are compatible with it. With some reservations to be noted below I agree with Dowe’s general conclusion, but in the course of his argument there are a number of false statements and misrepresentations of detail that require comment. I will not be able to (...) deal with all of them in this brief note. (shrink)

Some elementary properties of tachyons are described and then it is argued that the claim that (T) Tachyons exist, is incompatible with the truth of the Special Theory of Relativity (STR). First it is argued that from T, STR, and the negation of the principle that (Pl) Effect never precedes cause, one can derive a paradoxical conclusion, one of the so-called "causal paradoxes". An obvious response is to affirm (Pl), but then it is argued that (Pl) and (T) entail that (...) STR is false. (shrink)

Wittgenstein's remarks in his Tractatus on mathematics are quite obscure. Benacerraf and Putnam wrote, "In his Tractatus Loqico-Philosophicus, Wittgenstein maintained, following Russell and Frege, that mathematics was reducible to logic." On the other hand, Max Black claims, "Wittgenstein does not regard mathematics as reducible to logic, in the manner of Whitehead and Russell." I offer a detailed commentary upon Wittgenstein's remarks, concluding that his views most likely do not follow those of Frege and Russell. I reject a criticism of Wittgenstein (...) presented by Black but find severe shortcomings in the view I take Wittgenstein to be presenting. (shrink)

In this paper I argue that the clash of the Sellars’ two images is particularly acute in the case of time. In Time and the World Order Sellars seems embarked on a quest to locate manifest time in Minkowski spacetime. I suggest that he should have argued for the replacement of manifest time with the local, path-dependent time of the “scientific image”, just as he suggests that manifest objects must be replaced by their scientific counterparts.

In a ‘Letter from Washington’ in The New Yorker, Elizabeth Drew reported some speculation regarding the mental processes of Ronald Reagan. In Drew’s words:The curious process Drew describes is clearly important in many ways -historically, politically, and perhaps legally. We contend that there is even some epistemological significance to Reagan’s method for the fixation of belief. We shall argue, in particular, that some of those curiously insulated beliefs which Reagan possesses qualify as knowledge under at least one leading causal reliabilist (...) theory of knowledge- that presented by F. Dretske in Knowledge and the Flow of Information. But, as we detail the structure of such beliefs, what is probably evident already will emerge quite clearly, viz., that these beliefs do not amount to knowledge. (shrink)

Hilary Putnam argued that the special theory of relativity shows that there can be no temporal becoming. Howard Stein replied by defining a becoming relation in Minkowski spacetime. Clifton and Hogarth extended and sharpened Stein’s results. Game over? To the contrary, it has been argued that the Stein-Clifton-Hogarth theorems actually support Putnam’s contention, in that if an apparently minimal condition is put on the becoming relation, then these theorems entail that the becoming relation must be the universal relation. I recount (...) this dialectic in some detail and then try to define and defend a becoming relation based on a present that does indeed consist of more than one point or event but still satisfies the sort of objectivity requirements that Stein-Clifton-Hogarth require of a becoming relation. This present is not a global hyperplane or surface, however; it is a local structure. I close with some methodological remarks about the relation between the present and the real and about the importance of the specious or psychological present. (shrink)

There is a wide-spread belief that we know more about the past than we do about the future. It may be difficult to express the content of this belief exactly and it may turn out that, when we find some precise expression of this belief, it is not so obviously true. I shall assume, however, that there is something to a belief shared not only by eminent philosophers but by cultures wholly distinct from our own, as the following quote indicates.We (...) know where the future is. It’s in front of us. Right? It lies before us—a great future lies before us—we stride forward confidently into it, every commencement, every election year. And we know where the past is. Behind us, right? So that we have to turn around to see it, and that interrupts our progress ever forward into the future, so we don’t really much like to do it. (shrink)

This volume is the record of a symposium on the structer of scientific theories held in urbana, Illinois in the spring of 1969. ofSeven main papers, commentaries, discussions, and a postscript form the bulk of the book. The rest is a nearly 240-page monograph-in-the-guise-of-an-introduction by the editor titled “The Search for Philosophic Understanding of Scientific Theories”.

John Earman's new book,World Enough and Space-Time, is a brisk account of the controversy between space-time absolutists and relationists. The book is intended, one is told, to be “appropriate for use in an upper-level undergraduate or beginning graduate course in the philosophy of science”, but Earman's no-holds-barred approach to the mathematics of space-time theories will have bludgeoned most philosophical readers, undergraduate or beyond, into submission long before it is revealed that Pirani and Williams “have studied the integrability conditions for Born-rigid (...) motions in curved space-times and have shown that space-times of Petrov types II, III, and N do not admit of nonrotating Born-rigid motions”. I say this sadly, because Earman's book is a discerning review of an important literature, and most of its main arguments can be grasped even if some technical details remain out of reach. The more you reach for those details, the more compelling the book will become. (shrink)

Barry Dainton wrote Time and Space “to provide an introduction to the contemporary philosophical debate that presupposes little or nothing by way of prior exposure to the subject, but that will also take the interested and determined reader quite a long way”. He has achieved much of what he intended in this difficult enterprise. He covers the major arguments in a fair-minded way, writes clearly, and has found a good illustrator to provide a host of diagrams that his student readers (...) in particular will find helpful. The book also has a helpful glossary and list of web resources, as well as a brief bibliography and index. (shrink)