about  |  news  |  site map



an overview of the philosophy of mental time

Last update: December 5, 2013
Contributors: Lajos Brons

"Mental time" is the awareness of time: of past, present, and future. It involves aspects of memory, future-oriented concern, experience and expression of time, and so forth. "Philosophy of mental time" is the study of philosophical aspects hereof. Hence, philosophy of mental time is primarily concerned with experience and awareness of time (broadly conceived).
However, most philosophy of time (rather than that of mental time) is concerned with metaphysical aspects of time, which may seem to be an entirely different topic. Nevertheless, they are not completely separate. Philosophy grew out of the critical reflection on more practical concerns. Often, answers to those relatively practical questions (How to live well?, for example) turn out to depend on much "deeper" foundational issues: on metaphysics or epistemology, for example. The same is true in the philosophy of time (broadly conceived): metaphysical issues are often foundational, and as such restrict or even determine answers to philosophical questions that are closer to ordinary experience. In other words, even though we are primarily interested in mental time, we cannot ignore the metaphysics of time in this overview.

references and further readings
Callender, C. (2011), The Oxford Handbook of Philosophy of Time, Oxford: OUP. Hereafter: OHPT.
Dyke, H. & A. Bardon (2013), A Companion to the Philosophy of Time, Chichester: Wiley-Blackwell. Hereafter: BCPT.



table of contents

metaphysics of time
A-theory vs. B-theory
presentism vs. eternalism
time travel
the "passage" or "flow" of time
asymmetry and direction of time
the "shape" of time
discrete time
3Dism vs. 4Dism
fatalism
probability and chance
reductionism
events
identity through time
time and/in physics

experience of time
What do we perceive when we "perceive" time?
perceiving the past
duration of the experienced present
memory and time order
time awareness
the phenomenology of time
mental time travel, self-consciousness, and animal minds
future concern, fear of death, and personal identity through time
death: harm, asymmetry, and the afterlife
time in psychology and cognitive science
the expression of time in language
time and action
time in ethics and social philosophy




metaphysics of time

The metaphysics of time is concerned with a number of questions about the nature of time. Saint Augustine wrote in his Confessions (5th ct.): "What is time? If no one asks me, I know what it is. If someone asks me to explain it, I do not know." Rather than trying to answer the general question "What is time?" most 20th century philosophers have – probably mostly for that reason – focused their attention on more specific questions. In the same way that metaphysical issues in general are (often) foundational for answers to more practical concerns, there is one such "specific question" that seems to be foundational for most other metaphysical problems of time. This question is whether time consists of a past, present, and future, or alternatively is an ordered series of moments? The first of these two options is called the A-theory; the second the B-theory. The choice between A and B-theory limits the options in other metaphysical issues: For the A-theorist there is a different set of answers possible to questions about existence, identity through time, fatalism, the direction of time, time travel, and so forth, than for the B-theorist, and this difference ultimately trickles down to philosophical problems about the experience of time (i.e. our main concern). In the background of the A vs. B controversy (and what follows from it) lurks a possibly even more fundamental question: To what extent is time similar to space? Are spatial metaphors for time just metaphors or not? We will mostly set aside that issue, however, and start this overview of the metaphysics of time with the A vs. B controversy.

references and further readings
Most of the chapters in OHPT and BCPT.
Markosian, N. (2008), "Time", SEP. (An excellent overview of metaphysical aspects of time. Many of the suggested further readings in the metaphysiscs part of this overview are borrowed from this article.)

[top of page]


A-theory vs. B-theory

In "The unreality of time", McTaggart (1908) distinguished two ways of ordering temporal locations: the A series and the B series. The A series relates all temporal locations to the present moment; it consists of (one-place) properties like being present, being one week in the future, being two years in the past, and so forth. The B series relates all temporal locations to other temporal locations; it consists of (two-place) relations such as being one week later than, being one year earlier than, and so forth. According to McTaggart, only the A series really captures the essence of time, but the A series is contradictory. He argues that the following two propositions about the A series are both true, but contradict each other, and therefore, that time is unreal:

1) Different A properties are mutually exclusive. (That is, an event cannot both be one week in the future and two years in the past.)
2) Each moment must have all A properties. (Because an event that is one week in the future will, in 103 weeks, be two years in the past.)

McTaggart anticipates a response that rejects (2) by claiming that:

2a) At any time t, each moment has only one A property. (That is, the same event has the properties of being one week in the future and being two years in the past at different times.)

This response fails because it leads to an infinite regress. "Times t" and "moments" both refer to temporal locations; they are synonyms (except that they name different temporal locations in 2a). (2a) can, therefore, be rephrased as:

2a') At any second-order moment, each first-order moment has only one A property.

(Although it should be noted that this is not McTaggart’s terminology.) For example, today event X is two days in the future, and in one week exactly it will be five days in the past. The time of the occurrence of X is the first-order moment; "today" and "in one week exactly" are the second-order moments (i.e. the moments when temporal references to X are made). However, these second-order moments also have A properties (such as being in one week exactly), which means that either they have different A properties at all times as in (2) leading to the same contradiction as above, or they have different A properties at different times as in (2a), introducing third-order moments (i.e. the "second-order moments" of those second-order moments as first-order moments), for which the same would be true, and so forth.

Few philosophers have been willing to accept McTaggart’s conclusion that time is unreal. Instead, many have accepted that the B series is all there is. These philosophers, B-theorists, claim that all talk about A properties can be reduced to B relations. Their opponents, the A-theorists, however, argue that this takes insufficient account of the passage of time. For the B-theory, time is nothing but an ordered list of moments, while for the A-theory, every moment is identified by its relation to the present. For most B-theorists, therefore, the passage of time is merely how we experience time, it is a mind-dependent phenomenon, but for A-theorists, the passage of time is an essential feature of reality.

references and further readings
Bourne, C. (2006), A Future for Presentism, Oxford: OUP.
Le Poidevin, Robin (ed.) (1988), Questions of Time and Tense, Oxford: OUP.
Markosian, N. (1993), "How Fast Does Time Pass?", Philosophy and Phenomenological Research 53, pp. 829-44.
McTaggart, J.M.E. (1908), "The Unreality of Time", reprinted In: Le Poidevin, Robin, and McBeath, Murray (eds.) (1993), The Philosophy of Time, Oxford: OUP, pp. 23-34.
Mellor, D.H. (1998), Real Time II, London: Routledge.
Mozersky, M.J. (2013), "The B-Theory in the Twentieth Century", in: BCPT, pp. 167-82.
Prior, A.N. (1967), Past, Present, and Future, Oxford: OUP.
Prior, A.N. (1968), Papers on Time and Tense, Oxford: OUP.
Prior, A.N. (1972), "The Notion of the Present", in: J.T. Fraser, F.C. Haber, & G.H. Müller (eds.), The Study of Time, Berlin: Springer, pp. 320-3.
Sider, T. (2001), Four-Dimensionalism: An Ontology of Persistence and Time, Oxford: OUP. (This book is also relevant for several of the following topics.)
Smart, J.J.C. (1949), "The River of Time", Mind 58, pp. 483-94
Smart, J.J.C. (1963), Philosophy and Scientific Realism, London: Routledge.
Smith, Qu. (1993), Language and Time, Oxford: OUP.
Williams, D.C. (1951), "The Myth of Passage", Journal of Philosophy 48, pp. 457-72.
Zimmerman, D. (2005), "The A-theory of Time, the B-theory of Time, and 'Taking Tense Seriously'", Dialectica 59, pp. 401-457.
Zimmerman, D. (2011), "Presentism and the Space-Time Manifold", in: OHPT, pp. 163-244.
Zwart, P.J. (1976), About Time, Dordrecht: North-Holland.
(See also the next topic.)

[top of page]


presentism vs. eternalism

If time passes, as the A-theory claims, then only present objects exist. This position is called presentism. If, however, time is much more like space, as the B-theory claims; that is, if time is an ordered series of moments and there are no real temporal properties, but only temporal relations (e.g. no one-place being one week in the future, but two-place being one week later than), then objects at any moment exist. According to eternalism, not just present objects, but also past and future objects exist. (There is a third position in this debate, which claims that both past and present objects exist, but not future objects. Like presentism, this position is related to the A-theory.)
Presentism (and the third position) has considerable difficulty explaining talk about non-present objects. If only present objects exist, then what is talk about Aristotle referring to? And how is it possible that the claim that Sauropoda were larger than Microraptors (i.e. a relation between two kinds of non-present objects) is perfectly meaningful? This problem is a special variant of a class of more general problems about existence and its relation with existential quantification (i.e. what it means to say that something exists), which are concern of the highly specialized branch of metaphysics called meta-ontology. (And to a large extent, the problem may depend on the adoption of the current orthodoxy in that branch.)

references and further readings
Adams, R.M. (1986), "Time and Thisness", Midwest Studies in Philosophy 11, pp. 315-329.
Bigelow, J. (1966), "Presentism and Properties", Philosophical Perspectives 10, pp. 35-52.
Bourne, C. (2006), A Future for Presentism, Oxford: OUP.
Hinchliff, M. (1966), "The Puzzle of Change", Philosophical Perspectives 10, pp. 119-36.
Keller, S. & M. Nelson (2001), "Presentists Should Believe in Time-Travel", Australasian Journal of Philosophy 79, pp. 33-345.
Markosian, N. (2003), "A Defense of Presentism", in: D. Zimmerman (ed.), Oxford Studies in Metaphysics, Vol. 1, Oxford: OUP.
McCall, S. (1994), A Model of the Universe, Oxford: Clarendon.
Miller, K. (2013), "Presentism, Eternalism, and the Growing Block", in: BCPT, pp. 345-64.
Mozersky, M.J. (2011), "Presentism", in: OHPT, pp. 122-44.
Sider, T. (1999), "Presentism and Ontological Commitment", Journal of Philosophy 96, pp. 325-47.
Tooley, M. (1997), Time, Tense, and Causation, Oxford: OUP.
Zimmerman, D. (1996), "Persistence and Presentism", Philosophical Papers 25, pp. 115-26.
Zimmerman, D. (1998), "Temporary Intrinsics and Presentism", in: P. van Inwagen & D. Zimmerman (eds.), Metaphysics: The Big Questions, Malden: Blackwell, pp. 206-19.
Zimmerman, D. (2011), "Presentism and the Space-Time Manifold", in: OHPT, pp. 163-244.
(See also the previous topic.)

[top of page]


time travel

Is time travel logically (rather than physically) possible? In addition to familiar problems such as the grandfather paradox, this question is also related to the previous issue: if presentism is right, then neither the past nor the present exists, and therefore, one could not travel there (i.e. time travel is impossible). An argument against the logical impossibility of time travel is that we can make sense of time travel stories, while we cannot make sense of logical impossibilities such as being both red and green all over.

(See also mental time travel below.)

references and further readings
Earman, J. (1995), "Recent Work on Time Travel," in: S. Savitt (ed.), Time's Arrows Today: Recent Physical and Philosophical Work on the Direction of Time, Cambridge: CUP, pp. 268-310.
Keller, S. & M. Nelson (2001), "Presentists Should Believe in Time-Travel", Australasian Journal of Philosophy 79, pp. 33-345.
Kutach, D. (2013), "Time Travel and Time Machines", in: BCPT, pp. 301-14.
Lewis, D. (1986), "The Paradoxes of Time Travel," in: Philosophical Papers, Vol. 2, Oxford: OUP.
Meiland, J.W. )1974), "A Two-Dimensional Passage Model of Time for Time Travel", Philosophical Studies 26, pp. 153-73.
Smeenk, C. & C. Wüthrich (2011), "Time Travel and Time Machines", in: OHPT, pp. 577-630.
Thorne, K.S. (1994), Black Holes and Time Warps: Einstein’s Outrageous Legacy, New York: Norton.
Yourgrau, P. (1999), Gödel Meets Einstein: Time Travel in the Gödel Universe, Peru IL: Open Court.

[top of page]


the "passage" or "flow" of time

A-theorists claim that time passes or flows; B-theorists claim that the passage of time is just how we experience time, but is not real.

(See also A-theory vs. B-theory.)

to be extended

references and further readings
Markosian, N. (1993), "How Fast Does Time Pass?", Philosophy and Phenomenological Research 53, pp. 829-44.
Price, H. (2011), "The Flow of Time", in: OHPT, pp. 276-311.
Prosser, S. (2013), "The Passage of Time", in: BCPT, pp. 315-27.
Smart, J.J.C. (1949), "The River of Time", Mind 58, pp. 483-94
Williams, D.C. (1951), "The Myth of Passage", Journal of Philosophy 48, pp. 457-72.
(See also the next topic, and presentism vs. eternalism.)

[top of page]


asymmetry and direction of time

to be added

(Thermodynamic and causal asymmetry. Etc. – Causes precede their effects, but why should this necessarily be so; especially if the B-theory/eternalism is right? )

references and further readings
Earman, J. (2011), "Sharpening the Electromagnetic Arrow(s) of Time", in: OHPT, pp. 485-527.
Frisch, M. (2013), "Time and Causation", in: BCPT, pp. 282-300.
Kutach, D. (2011), "The Asymmetry of Influence", in: OHPT, pp. 247-75.
North, J. (2011), "Time in Thermodynamics", in: OHPT, pp. 312-350.
Price, H. (1994), "A Neglected Route to Realism About Quantum Mechanics", Mind 103, pp. 303-336.
 Price, H. (1996), Time's Arrow and Archimedes' Point: New Directions for the Physics of Time, Oxford: OUP.
Savitt, S. (ed.) (1995), Time's Arrows Today: Recent Physical and Philosophical Work on the Direction of Time, Cambridge: CUP.
Sklar, L. (1974), Space, Time, and Spacetime, Berkeley: University of California Press.
Wallace, D. (2013), "The Arrow of Time in Physics", in: BCPT, pp. 262-281.
(See also the previous and following topic.)

[top of page]


the "shape" of time

If time is to be represented spatially, what would be its shape? It is often assumed that it would be a line, but other answers have been suggested. Rather than a line, but still similar, it could be a ray (with one end point) or a line segment (with two). Or it could be a circle (or other kind of closed loop). These suggestions assume a singular "path" of time, but time could also be branching, or there could be multiple parallel time lines (or other shapes) that never touch. In addition to the question which of these figures most accurately represents the actual "shape" (or topology) of time, there is a second question whether this is necessarily the case, or mere contingency or accident.

references and further readings
Newton-Smith, W.H. (1980), The Structure of Time, London: Routledge & Kegan Paul.
Swinburne, R. (1966), "The Beginning of the Universe", Proceedings of the Aristotelian Society, Supplementary Volume 50, pp. 125-38.
Swinburne, R. (1968), Space and Time, London: Macmillan.
(See also the previous topic.)

[top of page]


discrete time

A related question is whether time is continuous or discrete. A line is continuous, and similarly it is generally believed that time is continuous, but the idea that time is discrete, that there are smallest amounts of time that have non-zero duration, is not necessarily incoherent.

(A closely related topic that is primarily of historical interest, is the historical development of the idea of zero duration. In contemporary thought, "moments" have no duration in the same way that points on a line have no size. Moments are points in time, and similarly non-extended. This is a rather new idea in Western thought, however, and is probably related to the invention of the infinitely small in the 19th century. Indeed, in 19th century thought, moments were generally considered to have some very small duration. In Indian philosophy, on the other hand, the idea of zero duration is much older. Abhidharma metaphysics (3rd ct. BCE) argued that reality consist of spatially and temporally non-extended dharmas.)

references and further readings
Van Bendegem, J.P. (2011), "The Possibility of Discrete Time", in: OHPT, pp. 145-62.
(More to be added?)

[top of page]


3Dism vs. 4Dism

Do objects have temporal parts? For a presentist, only the present object exists, but for a eternalist, past and future objects also exist. If one takes the latter position, are my past, present, and future selves all part of one and the same object, of some kind of "space-time worm"? This view is called four-dimensionalism, perdurantism, or 4Dism. The opposing point of view (that only the present object exists) is called three-dimensionalism, endurantism, or 3Dism.

references and further readings
Balashov, Y. (2011), "Persistence", in: OHPT, pp. 13-40.
Haslanger, S. (1989), "Persistence, Change, and Explanation", Philosophical Studies 56, pp. 1-28.
Haslanger, S. (1989), "Endurance and Temporary Intrinsics", Analysis 49, pp. 119-25.
Haslanger, S. (1994), "Humean Supervenience and Enduring Things", Australasian Journal of Philosophy 72, pp. 339-59.
Hawley, K. (2001), How Things Persist, Oxford: OUP.
Heller, M. (1990), The Ontology of Physical Objects: Four Dimensional Hunks of Matter, Cambridge: CUP.
Hudson, H. (2001), A Materialist Metaphysics of the Human Person, Ithaca: Cornell University Press.
Lewis, D. (1986), On the Plurality of Worlds, London: Blackwell.
Quine, W.V.O. (1960), Word and Object, Cambridge MA: MIT Press.
Rea, M.C. (1998), "Temporal Parts Unmotivated", The Philosophical Review 107, pp. 225-60.
Sider, T. (2001), Four-Dimensionalism: An Ontology of Persistence and Time, Oxford: OUP.
Thomson, J.J. (1983), "Parthood and Identity Across Time", Journal of Philosophy 80, pp. 201-20.
Van Inwagen, P. (1990), "Four-Dimensional Objects", Nous 24, pp. 245-55.
Williams, D.C. (1951), "The Myth of Passage", Journal of Philosophy 48, pp. 457-72.
Zimmerman, D. (1996), "Persistence and Presentism", Philosophical Papers 25, pp. 115-26.
(See also presentism vs. eternalism, and identity through time.)

[top of page]


fatalism

Fatalism is one of the oldest philosophical problems about time. Although fatalism seems especially problematic for eternalism – if the future (already) exists, how can one change it – one common argument for fatalism may be equally problematic for presentism. This argument is, more or less, the following:

1) There are propositions about all future events.
2) Every proposition is either true or false.
3) Therefore (from 1 and 2), there is a set of true propositions about all future events.
4) If there is such a set of true propositions, then these correctly predict the future, and thus that future is unavoidable.

Which leads to (or is) fatalism. Typically, philosophers who reject this argument attack either (2) or (4) or both.

(2) is often rejected on the ground that there is a third option: propositions can be indeterminate. For example, the proposition that it will rain in exactly one week from now, is indeterminate rather than true or false. It will be true or false in one week from now (and will keep that truth value from that time onwards), but until that time, it is indeterminate. This response to the argument for fatalism depends, of course, on the assumption that it makes sense to say that propositions have truth values at times, rather than truth values simpliciter, and whether it does is not immediately obvious. This problem is closely related to the A vs. B controversy (see above) and McTaggart’s arguments against the A series. Another problem with this response is that it seems to confuse being indeterminable with being indeterminate, while those are not obviously the same.

Step (4) can be rejected, for example, on the grounds that the mere existence of a set of true propositions is "harmless" if (a) it is not known which propositions about the future are true, and if (b) one does not accept the correspondentist thesis that true propositions entail (the existence of) facts as truth-makers. (See, for example, Wheeler 2014.)

references and further readings
Aristotle, De Interpretatione.
Bourne, C. (2011), "Fatalism and the Future", in: OHPT, pp. 41-67.
Van Inwagen, P. (1983), An Essay on Free Will, Oxford: Clarendon.
Wheeler, S.C. (2014), Neo-Davidsonian Metaphysics: From the True to the Good, Chapter 7, Routledge.
(See also presentism vs. eternalism.)

[top of page]


probability and chance

What is the nature of probability and chance if either presentism or eternalism is true? In case of the latter, does the notion of chance make sense?

to be extended

references and further readings
Hoefer, C. (2011), "Time and Chance Propensities", in: OHPT, pp. 68-90.
(More to be added.)

[top of page]


reductionism

Does time exist independently from the events occurring in time, or can it be reduced to (the relations between) those events? Would it be possible that during some period of time absolutely nothing happens, nothing changes, nothing moves? If the answer to the latter question is "yes", then time exists independently from the events in time; if it is "no", then time seems to be reducible to (the relations between) those events.

The main arguments for reductionism are (1) that time, by definition, is nothing but a collection of relations between events, and (2) that we could have no reason to belief that something like the second question happened. If absolutely nothing would happen, change, move, and so forth, our clocks or other devices of time measurement would stop for that period as well, and – along with everything else – would resume their normal function at the end of that "empty" period. We would have no way to know this empty period existed and how long it took. Moreover, it is not immediately obvious to say that it makes sense that this empty period has a determinate duration: if time can only be measured by means of changes (movements, etc.), then it is fundamentally impossible to specify the duration of empty time.

references and further readings
Newton-Smith, W.H. (1980), The Structure of Time, London: Routledge & Kegan Paul.
Shoemaker, S. (1969), "Time Without Change," Journal of Philosophy 66, pp. 363-81.
(More to be added.)

[top of page]


events

Events exist in time, and perhaps, time can be reduced to relations between events, but do events exist? Specifically, do events exist irreducibly? Underlying contemporary mainstream metaphysics is Quine’s notion of ontological commitment: our best scientific theories, but also our ordinary ways of talking commit us to the existence of certain (kinds of) things. To exist in a metaphysically relevant sense means to be the object of ontological commitment and not to be reducible to anything more basic. Davidson (1967) famously argued that action sentences and adverbs commit us to the existence of events.

to be extended

references and further readings
(To be added.)

[top of page]


identity through time

What makes me-now, and me-in-one-week-from-now the same person? What makes mount Fuji seen from my window and the volcano that erupted in December 1707 the same mountain? For a 4Dist, they would be the same entity because they are part of the same space-time worm, but that does not answer the question, of course. The question then, would be: What makes them part of the same space-time worm? This is the problem of identity over time: what makes two objects existing at two different times numerically the same object?

to be extended

references and further readings
Goswick, D.L. (2013), "Change and Identity over Time", in: BCPT, pp. 365-86.
(More to be added.)
(See also 3Dism vs. 4Dism.)

[top of page]


time and/in physics

What is the relationship between philosophy and time and physics? Are there philosophical implications of relativity, quantum mechanics, thermodynamics, and so forth?

to be extended

references and further readings
Chapters 12, and 14 to 16 in BCPT; chapters 10 and 16 to 13 in OHPT.
(More to be added?)

[top of page]



experience of time

The most fundamental question with regards to the experience of time regards the how of time experience: How do we experience time? Answering this question involves both psychology and philosophy (as well as other disciplines), but the focus will be on philosophical aspects of the experience of time here. The experience of time involves two related, but distinct aspects: perception of time and conscious awareness of time. Of course, the second depends on the first, but the first is possible without the second.

references and further readings
Chapters 23 to 32 in BCPT.
Ismael, J. (2011), "Temporal Experience", in: OHPT, pp. 460-82.
(More to be added.)

[top of page]


What do we perceive when we "perceive" time?

There is no particular, single sense (organ) that we use to perceive time, and arguably, we do not perceive time itself but events or changes in time, and possibly temporal relations as well. But how is this possible? What we perceive is present and perceived as such, and a temporal relation involves at least one event that is not present. If we "perceive" event A to follow event B (with more or less time in between), then at the time of our perception of A, we do not actually perceive B (because it is in the past), but only remember it. Perception – strictly speaking – does not include memory (although it may require memory, but that is another issue), and therefore, we do not perceive B and, by implication, its temporal relation with A.

For the same reason, we cannot perceive duration or the passing of time. Duration implies an interval of time between two points in time, two events, but if we can only perceive the present, then we can never perceive this interval, this passing. Of course, the implication that we cannot perceive temporal relations or the passing of time conflicts with common sense (perhaps, even with "good" sense), which may mean that the strict definition of perception is too strict.

references and further readings
Dainton, B. (2013), "The Perception of Time", in: BCPT, pp. 389-409.
Friedman, W.J. (1990), About Time: Inventing the Fourth Dimension, Cambridge MA: MIT Press.
Pöppel, E. (1978), "Time Perception", in: R. Held et al. (eds.), Handbook of Sensory Physiology, Vol. VIII: Perception, Berlin: Springer.
(More to be added.)

[top of page]


perceiving the past

The above discussion depends on the claim that we cannot perceive the past, but it does not explain why that is the case. Underlying the debate(s) in the metaphysics of time (see above) is a disagreement about the extent of similarity between space and time. This similarity – or lack thereof – also plays a role in the perception of time: we can perceive far away things, but not past things or future things. If perception is causal and causes always precede their effects, than we cannot see future things, but there is no similar reason why we would be unable to perceive past things (of course, strictly speaking all perception is perception of past things because light and sound, etc. take time to reach the senses, but that is not the sense of "past" intended here). If the B-theory/eternalism (see above) is right, then there does not seem to be a prima facie reason why we cannot perceive past things, but there must be one (given that we do not actually perceive past things).

references and further readings
(To be added.)

[top of page]


duration of the experienced present

Contrary to the above, a strict definition of perception would not imply the impossibility of perceiving the passing of time if we perceive change or passing in the present itself. Metaphysics informs us that the present has no duration (but see "discrete time" above), but perhaps our actual experience ignores metaphysical insights.
 
As mentioned, what we perceive is present, but we perceive motion, and therefore motion is present. However, motion requires duration, and thus, the experienced present has duration. This is called "the specious present". Similarly, we experience certain kinds of temporally extended events, such as a short musical phrase, to be wholly in the present. However, even within that experienced extended present, there is a temporal order: the notes in the short phrase do not sound together. This seems contradictory: how can something both be temporally ordered and wholly present? A possible answer is that our minds operate with two different notions of "present" at the same time – one extended and one non-extended – that are used in different cognitive systems (perhaps the first in more "primitive" perception, and the latter in rationalization of and reflection on perception).

references and further readings
James, W. (1890), The Principles of Psychology, New York: Henry Holt.
Le Poivedin, R. (2007), The Images of Time: An Essay on Temporal Representation, Oxford: OUP.
(More to be added.)

[top of page]


memory and time order

Memory plays a central role in the perception/experience of time (as illustrated by the above discussion), but this raises various philosophical problems. Epistemological problems such as the reliability of memory are, perhaps, among the more obvious, but perception of duration (if memory is allowed in/as perception), of the passing of time, and of time order (both in the present, if the above is right, and beyond the present) require memories as more or less fixed points of reference. The question is: How do we actually perceive time order? Are perceptions "time-stamped", or do we add order unconsciously to make sense of the causal order of events? And if it is the latter, what does that mean for the perception of time order, duration, and so forth?

references and further readings
Dennett, D. (1991), Consciousness Explained, London: Allen Lane.
Fernández, J. (2013), "Memory", in: BCPT, pp. 432-43.
Mellor, D.H. (1998), Real Time II, London: Routledge.
(More to be added.)

[top of page]


time awareness

Awareness of something is consciousness of that thing, and awareness of time (or "mental time") is, therefore, consciousness of time. Humans are consciously aware of time, but whether other animals are (and/or to what extent) is less clear.

to be extended

references and further readings
(To be added.)

[top of page]


the phenomenology of time

to be added

references and further readings
(To be added.)

[top of page]


mental time travel, self-consciousness, and animal minds

Human beings can imagine themselves to be at different times (and places). For example, memories can take the form of imagining oneself to be at the time of some past event, and people can imagine the consequences of their actions by imagining themselves to be in the future. This ability of mental time travel is often considered to be a necessary (and perhaps even sufficient) condition of self-consciousness. Whether there are other animals that have this ability is uncertain. Does instinctive storing of food imply planning for the future and does that imply mental time travel? Do certain kinds of memory imply mental time travel? There are both conceptual and empirical issues involved in these questions, but philosophically most interesting are their implications: if some species of non-human animals are capable of mental time travel (to some extent), that might imply that they are self-conscious. It is difficult to overstate the importance of such a finding for the philosophy of animal minds. This, however, ignores the equally important philosophical question whether the ability of mental time travel is indeed a condition of self-consciousness, and if so, what kind (necessary or sufficient).

references and further readings
Corballis, M.C. (2007), "The Evolution of Consciousness", in: P.D. Zelazo, M. Moscovitch, & E. Thompson (eds.), The Cambridge Handbook of Consciousness, Cambridge: CUP, pp. 571-95. (Not philosophy, but an overview of research on the evolution of (self-)consciousness with a section on mental time travel in animals.)
DeGrazia, D. (2009), "Self-awareness in Animals", in: R.W. Lurz (ed.), The Philosophy of Animal Minds, Cambridge: CUP, pp. 201-17.
Menzel, R. & J. Fischer (eds.) (2011), Animal Thinking: Contemporary Issues in Comparative Cognition, Cambridge MA: MIT Press. (Not philosophy, but a fairly recent overview of the state of research on animal cognition with several chapters on planning and other time-related issues.)
(More to be added.)

[top of page]


future concern, fear of death, and personal identity through time

In extension of the above topic, mental time travel into the future often is related to concern about the future: future concern can both motivate and follow from mental time travel into the future. Worrying about the future (as the negative version of future concern) may be the corollary of the ability of mental time travel (and therefore, perhaps, of self-consciousness). Of all worries about the future, the deepest and most fundamental is the fear of death.

In Buddhist philosophy, the fear of death is countered by a rejection of personal identity (through time). Identity through time was already mentioned above as a topic in the metaphysics of time, but it is – like many of the metaphysical topics mentioned – also directly relevant for the experience of time. According to Buddhist philosophy, there is no essence or aspect that stays the same throughout someone’s life, nothing to anchor a self or person too. Rather, the self is a convenient designator for a causal chain of memories; it is not something that really, or "ultimately" exists. Fully realizing this should lift the fear of death. (If I don’t really exist anyway, then the termination of my existence in death does not really terminate anything.) Within Western philosophy, the most influential rejections of the self on the (same or similar) grounds of lacking identity-conditions through time (i.e. a self as stable essence) are those by David Hume (1739) and Derek Parfit (1984).

Marc Slors (2004) and Mark Johnston (2010) suggest that personal identity through time depends on future concern: one is whom one is concerned about. According to Johnston, this would imply that significant future concern with the whole of humanity (or one’s family, or nation, or anything else that survives substantially longer than one’s own body, but it should be noted that Johnston did not mention these alternatives) implies a personal identification therewith and thus survival (after one’s bodily death) thereas.

(See also the next topic.)

references and further readings
Gallagher, S. (ed.) (2011), The Oxford Handbook of the Self, Oxford: OUP.
Hume, D. (1739), A Treatise on Human Nature.
Johnston, M. (2010), Surviving Death, Princeton: Princeton UP.
Liu, J.-L. & J. Perry (eds.) (2012), Consciousness and the Self: New Essays, Cambridge: CUP.
Parfit, D. (1984), Reasons and Persons, Oxford: Clarendon Press.
Siderits, M. (2003), Personal Identity and Buddhist Philosophy, Aldershot: Ashgate.
Siderits, M., E. Thompson, & D. Zahavi (eds.) (2011), Self, No Self? Perspectives from Analytical, Phenomenological, & Indian Traditions, Oxford: OUP.
Slors, M. (2004), "Care for One's Own Future Experiences", Philosophical Explorations 7, pp. 183-95.
Stokes, P. (2013), "Will it Be Me? Identity, Concern and Perspective", Canadian Journal of Philosophy 43.2, pp. 206-226
(More to be added.)

[top of page]


death: harm, asymmetry, and the afterlife

Aside from the fear of death (see above) there are a number of related philosophical problems about death. Perhaps, one of the oldest questions is whether there is an afterlife (i.e. whether we somehow (can) "survive" death). In a recent book, Mark Johnston (2010) discusses and rejects virtually all known theories of an afterlife, before suggesting one of his own (as mentioned in the previous section).

Assuming that there is no afterlife, death seems to harm the person dying, but how is it possible that someone who is dead – and thus does not exists – is harmed? Harm after death seems a contradiction, but suggesting that death does not harm someone seems even more absurd. Hence, there is a philosophical puzzle here. A related issue is the asymmetry between non-existence before birth and after death. In either case one does not exist, but only the second seems inherently bad.

references and further readings
Becker, E. (1973), The Denial of Death, New York: Simon & Schuster. (One of the most famous and influential books on the role of death and belief in an afterlife for human civilizations.)
Johnston, M. (2010), Surviving Death, Princeton: Princeton UP.
(More to be added.)

[top of page]


time in psychology and cognitive science

In the same way that results and theories in physics may be relevant for the metaphysics of time, results and theories in psychology, cognitive science, and some other sciences may be relevant for the philosophy of time experience. Research on memory seems especially relevant, given the central role of memory in the experience of duration and order, but there are many other questions where philosophy and empirical science overlap: Does the experienced present have duration, and if so, what is its approximate length? (And does the mind indeed employ two notions of the present?) How do we perceive extended events (such as motion, or musical phrases)?

references and further readings
(To be added.)

[top of page]


the expression of time in language

Human languages express time or tense in a variety of ways, and this raises a number of questions that may have philosophical implications. Do all languages indeed express time or tense? How do these "ways of expression" differ? Do these different "ways of expression" somehow influence thought (both in the psychological sense and that in the history of ideas)? And so forth.

Assessing the philosophical implications of answers to such questions depends on a further, methodological question, however: are the limits to actual linguistic variation necessary or contingent, or to put it differently, do possible and actual linguistic variation (necessarily) coincide? And if that is not the case, to what extent can we infer philosophical conclusions from empirical facts about language?

Of all topics in the philosophy of mental time, this is perhaps one of the most inter-disciplinary. Many of the questions mentioned belong to comparative/descriptive linguistics and/or formal semantics, or to psycho-linguistics or intellectual history. Some of these fields overlap with areas of philosophy (formal semantics and philosophy of language, especially), but much – if not most – of the research with regards to this topic takes place outside philosophy.

references and further readings
(To be added.)

[top of page]


time and action

to be added

references and further readings
(To be added.)

[top of page]


time in ethics and social philosophy

The main issue with regards to time in ethics and social/political philosophy concerns distributive justice. In many theories just policies or right actions, and so forth, distribute harms and benefits more or less fairly (but they disagree, of course, about what "fair" means, among others). The question is, who should be taken into account in assessing the fairness of a distribution: only those alive now, or future generations as well? According to the principle of temporal neutrality, the temporal "location" of beings should be no concern; whether someone lives now or in the future should not matter in judging the fairness of a distribution of harms and benefits. Although this principle is accepted by many, it is not entirely uncontroversial.

to be extended

references and further readings
(To be added.)

[top of page]