The issue whether there is any necessary connection between time and change turns, I argue, on the problem of what constitutes an accurate measurement of how much time passes. Given a plausible hypothesis about how time is measured, Shoemaker’s well known argument that time can pass without change can be seen to be unsound. But Shoemaker’s conclusion is not therefore false. The same hypothesis about time measurement supports a revised version of Shoemaker’s argument, and the revised argument does establish that (...) the passage of a quantity of time does not require that change occur during that time. Though Shoemaker’s conclusion is vindicated, it does not follow that there is no necessary connection at all between time and change. On the contrary, there is a connection which is simply of a different kind from the one Shoemaker had in mind. (shrink)

It’s often claimed in the philosophical and scientific literature on temporal representation that there is no such thing as a genuine sensory system for time. In this paper, I argue for the opposite—many animals, including all mammals, possess a genuine sensory system for time based in the circadian system. In arguing for this conclusion, I develop a semantics and meta-semantics for explaining how the endogenous rhythms of the circadian system provide organisms with a direct information link to the temporal structure (...) of their environment. In doing so, I highlight the role of sensory systems in an information processing architecture. (shrink)

Sider (2001) and Hawley (2001) argue that, in order to account for the mere possibility of change, temporal parts must be as fine-grained as possible change, and hence as fine-grained as time. However, when dealing with metaphysical possibility, the fine-grainedness of actual time and the fine-grainedness of possible change can come apart. Once this is taken into account, we see that, on certain assumptions about the actual microstructure of time, the modal arguments of Sider and Hawley lead to the problematic (...) claim that temporal parts are more fine-grained than time. The utility of a temporal parts theory thus seems to be sensitive to metaphysically contingent facts concerning the microstructure of time. (shrink)

In this manuscript we initiate a systematic examination of the physical basis for the time concept in cosmology. We discuss and defend the idea that the physical basis of the time concept is necessarily related to physical processes which could conceivably take place among the material constituents available in the universe. As a consequence we motivate the idea that one cannot, in a well-defined manner, speak about time ‘before’ such physical processes were possible, and in particular, the idea that one (...) cannot speak about a time scale ‘before’ scale-setting physical processes were possible. It is common practice to link the concept of cosmic time with a space-time metric set up to describe the universe at large scales, and then define a cosmic time t as what is measured by a comoving standard clock. We want to examine, however, the physical basis for setting up a comoving reference frame and, in particular, what could be meant by a standard clock. For this purpose we introduce the concept of a `core' of a clock and we ask if such a core can - in principle - be found in the available physics contemplated in the various `stages' of the early universe. We find that a first problem arises above the quark-gluon phase transition where there might be no bound systems left, and the concept of a physical length scale to a certain extent disappears. A more serious problem appears above the electroweak phase transition believed to occur at $\sim 10^{-11}$ seconds. At this point the property of mass disappears and it becomes difficult to identify a physical basis for concepts like length scale, energy scale and temperature - which are all intimately linked to the concept of time in modern cosmology. This situation suggests that the concept of a time scale in `very early' universe cosmology lacks a physical basis or, at least, that the time scale will have to be based on speculative new physics. (shrink)

We present a Hilbert style axiomatisation for the set of formulas in the temporal language with F and P which are valid over non-transitive cyclical flows of time. We also give a simpler axiomatisation using the slightly controversial 'irreflexivity rule' and go on to prove the decidability of any temporal logic over cyclical time provided it uses only connectives with first-order tables.

: In this paper I discuss two puzzles that concern the sense in which consciousness can be described as ‘continuous’. The first puzzle arises out of recent work by Dainton and Tye, both of whom appear to oscillate between ascribing the property of ‘continuity’ to the stream of experience, and ascribing it to the objects of experience. The second puzzle concerns the notion that the stream of consciousness could be in some sense unreal or illusory—a puzzle stemming from the thought (...) that some of the brain processes underlying consciousness do not exhibit continuity. I argue that these problems can be solved by distinguishing between three possible bearers of the property of ‘continuity’—(1) the State of Consciousness, (2) the Stream of Experience, and (3) what is represented by experience—and two different senses of ‘continuity’—‘strict’ and ‘extreme’ continuity. I conclude by providing a positive account of the continuity of consciousness, according to which the State of Consciousness exhibits ‘strict’ continuity, and the Stream of Experience exhibits ‘extreme’ continuity. (shrink)

This paper considers a problem for dynamic presentism that has received little attention: its apparent inability to accommodate the duration of events (such as conscious experiences). After outlining the problem, I defend presentism from it. This defence proceeds in two stages. First, I argue the objection rests on a faulty assumption: that duration is temporal extension. The paper challenges that assumption on several different ways of conceiving of temporal extension. This is the negative case and forms the bulk of the (...) paper. Second, after diagnosing the error leading to the identification of duration with temporal extension, I outline a new presentist-friendly account of duration that avoids the problem. In particular, a non-reductive account of duration is offered that treats it as a primitive quality which bestows its possessor with a certain modal quality: that the possessor potentially does not change whilst there are changes in its environs. This is the positive case. Together the positive and negative cases provide presentism with an interesting and novel way of overcoming the problem of duration. (shrink)

Typical presentism asserts that whatever exists is present. Moderate presentism more modestly claims that all events are present and thus acknowledges past and future times understood in a substantivalist sense, and past objects understood, following Williamson, as “ex-concrete.” It is argued that moderate presentism retains the most valuable features of typical presentism, while having considerable advantages in dealing with its most prominent difficulties.

It is widely believed that relationism cannot make room for the possibility of intervals of time during which no changes occur. Benovsky has recently challenged this belief, arguing that relationists can account for the possibility of changeless time in much the same way as substantivalists do, thereby concluding that the two views are interchangeable for all theoretical purposes. This paper intends to defend the meaningfulness of the traditional dispute between substantivalists and relationists, by contending that the particular form of relationism (...) on which Benovsky has based his criticism is in fact alien to that debate. (shrink)

Van Bendegem has recently offered an argument to the effect that, if time is discrete, then there should exist a correspondence between the motions of massive bodies and a discrete geometry. On this basis, he concludes that, even if space is continuous, it should nonetheless appear discrete. This paper examines the two possible ways of making sense of that correspondence, and shows that in neither case van Bendegem’s conclusion logically follows.

There are three different degrees to which we may allow a systematic theory of the world to embrace the idea of relatedness—supposing realism about non-symmetric relations as a background requirement. (First Degree) There are multiple ways in which a non-symmetric relation may apply to the things it relates—for the binary case, aRb ≠ bRa. (Second Degree) Every such relation has a distinct converse—for every R such that aRb there is another relation R* such that bR*a. (Third Degree) Each one of (...) them applies in an order to the things it relates—with regard to the state that results from R's applying to a and b, either R applies to a first and b second, or it applies to b first and a second. Whereas the first degree is near-indubitable, embracing the second or third generates unwholesome consequences. The second degree embodies a commitment to the existence of a superfluity of distinct converses and states to which such relations give rise. The third degree embodies commitment to recherché facts of the matter about how the states that arise from the application of one non-symmetric relation compare to any other. It is argued that accounts that purport to offer an analysis of the first degree generate unwelcome second or third degree consequences. This speaks in favour of our adopting an account of the application of relations that's not an analysis at all, an account that takes the first degree as primitive. (shrink)

Perhaps the real paradox of Zeno's Arrow is that, although entirely stationary, it has, against all odds, successfully traversed over two millennia of human thought to trouble successive generations of philosophers. The prospects were not good: few original Zenonian fragments survive, and our access to the paradoxes has been for the most part through unsympathetic commentaries. Moreover, like its sister paradoxes of motion, the Arrow has repeatedly been dismissed as specious and easily dissolved. Even those commentators who have taken it (...) seriously have propounded solutions with which they profess themselves to be perfectly satisfied. So my question is: will Zeno's Arrow survive into the millennium just begun? (shrink)

According to a plausible and influential account of perceptual knowledge, the truth-makers of beliefs that constitute perceptual knowledge must feature in the causal explanation of how we acquire those beliefs. However, this account runs into difficulties when it tries to accommodate time perception -- specifically perception of order and duration -- since the features we are apparently tracking in such perception are not causal. The central aim of the paper is to solve this epistemological puzzle. Two strategies are examined. The (...) first strategy locates the causal truth-makers within the psychological mechanism underlying time perception, thus treating facts about time order and duration as mind-dependent. This strategy, however, is problematic. The second strategy modifies the causal account of perceptual knowledge to include a non-causal component in the explanation of belief-acquisition, namely chronometric explanation. Applying this much more satisfactory approach to perceptual knowledge of time, we can preserve the mind-independence of order and duration, but not that of time's flow. (shrink)

Friedrich Nietzsche’s theory of eternal recurrence is an essential part of his mature philosophy, but the theory’s metaphysical commitments and practical implications are both obscure. In this essay I consider only the metaphysical elements of the theory, with the aim of determining whether it is possible that we live our lives infinitely many times, as the theory maintains. I argue that the possibility of eternal recurrence turns on issues in personal identity and the metaphysics of time. As I proceed, I (...) also consider the relation between Nietzsche’s theory of eternal recurrence and theories of recurrence found in the work of Heraclitus, the Pythagoreans, and the Stoics. (shrink)

Personal time, as opposed to external time, has a certain role to play in the correct account of death and immortality. But saying exactly what that role is, and what role remains for external time, is not straightforward. I formulate and defend accounts of death and immortality that specify these roles precisely.

Leibniz's philosophy of time, often seen as a precursor to current forms of relationalism and causal theories of time, has rightly earned the admiration of his more recent counterparts in the philosophy of science. In this article, I examine Leibniz's philosophy of time from a new perspective: the role that tense and non-tensed temporal properties/relations play in it. Specifically, I argue that Leibniz's philosophy of time is best (and non-anachronistically) construed as a non-tensed theory of time, one that dispenses with (...) tensed temporal properties such as past, present, and future. In arguing for this thesis, I focus on the three facets of Leibniz's philosophy most relevant for evaluating his commitment to a B-theory of time: (1) the nature of change, (2) the reality of the future, and (3) the truth-conditions for tensed temporal statements. Despite prima facie evidence to the contrary, I show that a close examination of Leibniz's views on these topics provides compelling evidence for interpreting his philosophy of time as a B-theory of time. (shrink)

There are numerous occasions on which we need to reason about a finite number of events. And we often need to consider only those events which are given or which we perceive. These give rise to the Criteria of Finiteness and Closedness. Allen's logic provides a way of reasoning about events. In this paper I examine Allen and Hayes' axiomatisation of this logic, and develop two other axiomatisations based on the work by Russell and Thomason. I shall show that these (...) three axiomatisations are weakly equivalent, and that only the last two meet the Criteria of Finiteness and Closedness (to different degrees). I shall then examine two ways of constructing instants of time in a finite and closed world, i.e. the Russell construction and the Thomason construction. I shall prove that these two constructions are equivalent under certain conditions. (shrink)

Traynor identifies a tension between armchair reasoning telling us about the mereological structure of objects and empirical investigation telling us about the structure of spacetime. Section 1 explains, and bolsters, that tension. Section 2 discusses Traynor's resolution, and suggests some possible problems with it, whilst Section 3 discusses an alternative.

The present article aims to show that a subject can only fully grasp the concept of the past if she has some experiential, or recollective, memories of particular past events. More specifically, I argue that (1) in order for a subject to understand the concept of the past, it is necessary that the subject understand the concept of a particular past event in such a way that it might contribute to her understanding of the concept of the past. (2) But (...) then, in order for a subject to understand the concept of a particular past event in such a way that it might contribute to her understanding of the concept of the past, it is necessary that the subject have some recollective memories of particular past events. (C) Hence, a subject can only understand the concept of the past if she has some recollective memories of particular past events. I defend the premises of the present argument against various objections, indicate why we should accept both premises, and accordingly end by endorsing the argument's conclusion. (shrink)

Does mere passage of time have causal powers ? Are properties like "being n days past" causally efficient ? A pervasive intuition among metaphysicians seems to be that they don't. Events and/or objects change, and they cause or are caused by other events and/or objects; but one does not see how just the mere passage of time could cause any difference in the world. In this paper, I shall discuss a case where it seems that mere passage of time does (...) have causal powers : Sydney Shoemaker's (1969) possible world where temporal vacua (allegedly) take place. I shall argue that Shoemaker's thought-experiment doesn't really aim at teaching us that there can be time without change, but rather that if such a scenario is plausible at all (as I think it is) it provides us with good reasons to think that mere passage of time can be directly causally efficient. (shrink)

Information modeling (also known as conceptual modeling or semantic data modeling) may be characterized as the formulation of a model in which information aspects of objective and subjective reality are presented (the application), independent of datasets and processes by which they may be realized (the system).A methodology for information modeling should incorporate a number of concepts which have appeared in the literature, but should also be formulated in terms of constructs which are understandable to and expressible by the system user (...) as well as the system developer. This is particularly desirable in connection with certain intimate relationships, such as being the same as or being a part of. (shrink)

A set of axioms implicitly defining the standard, though not instant-based but interval-based, time topology is used as a basis to build a temporal modal logic of events. The whole apparatus contains neither past, present, and future operators nor indexicals, but only B-series relations and modal operators interpreted in the standard way. Determinism and indeterminism are then introduced into the logic of events via corresponding axioms. It is shown that, if determinism and indeterminism are understood in accordance with their core (...) meaning, the way in which they are formally introduced here represents the only right way to do this, given that we restrict ourselves to one real world and make no use of the many real worlds assumption. But then the result is that the very truth conditions for sentences about indeterministic events imply the existence of tensed truths, in spite of the fact that these conditions are formulated (in the indeterministic axiom) in terms of tenseless language. The tenseless theory of time implies determinism, while indeterminism requires the flow of time assumption. (shrink)

In this paper, I present a discrete solution for the paradox of Achilles and the tortoise. I argue that Achilles overtakes the tortoise after a finite number of steps of Zeno’s argument if time is represented as discrete. I then answer two objections that could be made against this solution. First, I argue that the discrete solution is not an ad hoc solution. It is embedded in a discrete formulation of classical mechanics. Second, I show that the discrete solution cannot (...) be falsified experimentally. (shrink)

The goal of this paper is to defend the general tenet that time travelers cannot change the past within B-theoretical models of time, independently of how many temporal dimensions there are. Baron Pacific Philosophical Quarterly, 98, 129–147 offered a strong argument intended to reach this general conclusion. However, his argument does not cover a peculiar case, i.e. a B-theoretical one-dimensional model of time that allows for the presence of internal times. Loss Pacific Philosophical Quarterly, 96, 1–11 used the latter model (...) to argue that time travelers can change the past within such model. We show a way to debunk Loss’s argument, so that the general tenet about the impossibility of changing the past within B-theoretical models is maintained. (shrink)

This document consists primarily of an excerpt (chapter 14) from the author’s book From Brain to Cosmos. In that excerpt, the author uses the concept of subjective fact developed earlier in the book to address a question about consciousness: which physical systems (organisms or machines) are conscious? (This document depends heavily upon the concept of subjective fact developed in From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to (...) Cosmos first. See the last page of this document for details on how to obtain those chapters.). (shrink)

This document consists primarily of an excerpt (chapter 5) from the author’s book From Brain to Cosmos. That excerpt presents an analysis of personal identity through time, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of an excerpt (chapter 6) from the author’s book From Brain to Cosmos. That excerpt presents an analysis of the problem of knowledge of other minds, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of excerpts (chapters 5 and 7-9) from the author’s book From Brain to Cosmos. These excerpts address some traditional philosophical problems about temporal flux and identity through time, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of an excerpt (chapter 13) from the author’s book From Brain to Cosmos. In that excerpt, the author presents a study of the notion of truth using the concept of subjective fact developed earlier in the book. The author argues that mind-body materialism is compatible with certain forms of metaphysical idealism. The chapter closes with some remarks on relativism with regard to truth. (This document depends heavily upon the concept of subjective fact developed in From Brain (...) to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.). (shrink)

This document consists primarily of excerpts (chapters 5 and 10-12) from the author’s book From Brain to Cosmos. These excerpts address several traditional problems about the histories of conscious subjects, using the concept of subjective fact that the author developed earlier in the book. Topics include the persistence of conscious subjects through time, the unity or disunity of the self, and the possibility of splitting conscious subjects. (These excerpts depend heavily upon the author’s concept of subjective fact as developed in (...) From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of that book first. See the last page of this document for details on how to obtain those chapters.). (shrink)

This document consists primarily of an excerpt (chapter 4) from the author’s book From Brain to Cosmos. That excerpt presents a study of a specific problem about knowledge: the logical justification of one’s knowledge of the immediate past. (This document depends heavily upon the concept of subjective fact that the author developed in chapters 2 and 3 of From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read those chapters first. See the last page of this (...) document for details on how to obtain those chapters.). (shrink)

The present work explores various ways in which contingent evidence can impact metaphysics, while advocating that, just as a scientific realist allows for ampliative inferences to the unobservable, ampliative inferences from possible evidence can warrant possibility claims that lie beyond the reach of sensorial imagination. In slogan form: possible evidence is a guide to possibility. Drawing on Shoemaker’s (1969) argument for the possibility of time without change, I advocate the following principle: If there is a possible world at which the (...) observable facts make it objectively reasonable to conclude that p, then we should conclude that p is possibly true. This provides a route to contingentism in metaphysics, for, if one considers that there are worlds in which the observable facts make it objectively reasonable to conclude that p, and worlds in which the observable facts make it objectively reasonable to conclude that not-p, then my principle tells us that we should conclude that possibly-p and possibly not-p, i.e. that p is contingent. This contingency in what is reasonable to conclude, I suggest, occurs most saliently in debates where evidence of phenomenal experience and empirical science are marshalled to support one theory over another. I also explore some consequences of taking possible evidence to be a guide to possibility in this way, among them being an interesting modal analogue of the lottery paradox. (shrink)

This is a draft for a revised edition of Mark Sharlow's book "From Brain to Cosmos." It includes most of the material from the first edition, two shorter pieces pertaining to the book, and a detailed new introduction.

A fallibilist theory of knowledge is employed to make sense of the idea that agents know what they are doing 'without observation' (as on Anscombe's theory of practical knowledge).