A Defense of the Tensed Theory of Time

The Coherence of Tenses

By Conrad Robinson

Introduction

The tensed theory holds that time is a dynamic aspect of existence. Time flows and objects change in time. The grammatical tenses used in everyday language, was, is, will be, have an ontological correspondence. The structure of time is mirrored by the structure of grammar. It is this flow of time that allows for certain propositions to undergo a real change in their truth value. E.g. ‘There will be a sea battle tomorrow,’ will be rendered true or false by temporal movement, but as of today, the statement has no truth value.

Past, present, and future, therefore, are radically different and mutually exclusive predicates. Every event must be one or the other, and no event can be more than one. Not only is this true grammatically (‘He will be in Boston yesterday’ is not a grammatically correct sentence), it is also true ontologically (A human cannot simultaneously be alive and be dead on Thursday, October 5^th).

There is something deeply intuitive about the tensed theory of time, yet, there are philosophers (and many physicists) who hold that the tensed theory is false and even incoherent. The controversy dates back to the beginning of the twentieth-century when the British idealist philosopher, J. M. Ellis McTaggart, published his infamous paper, “The Unreality of Time.”[1] In this paper McTaggart made what he felt was a fatal criticism of the tensed theory of time.

McTaggart is of course not the only opponent tensers face. He is, however, the most fundamental. My goal in this paper is a modest one, to demonstrate that tenses are coherent by explaining exactly how they differ from each other. I maintain that future is a tense that is applicable only to possible events i.e. events that do not have a current existence and indeed may never have an actual existence. I then consider and reject the idea that past and present are two ontologically different tenses. Past is ultimately reducible to present by one of two methods which can be termed the ‘postmodern approach’ and the ‘enduring present approach.’ After considering both positions I find more in favor of the enduring present approach.

McTaggart’s Argument

McTaggart readily admits that the idea of time’s transience does indeed correspond with the commonsense conception and experience of time; nevertheless, he holds that this conception is fatally flawed.

Whether we take [tenses] as relations of events (which seems the more reasonable view) or whether we take them as qualities of events, it seems… that they involve a contradiction.[2]

McTaggart sees tensers as adhering to two incompatible propositions:

1. [At any given time: past], present, and future are incompatible determinations.

2. [Yet also at any given time], every event has [all three determinations]. If M is past, it has been present and future. If it is future, it will be present and past. If it is present, it has been future and will be past. Thus all the three incompatible determinations are predictable of each event, which is obvious inconsistent with their being incompatible…[3]

One and two cannot both be correct and, given that logical contradictions cannot exist, McTaggart concludes that the tensed theory of time is false. (And given that the tensed theory is the best account of time and change available, nothing worth calling ‘time’ exists either.)
A tenser may try to respond to McTaggart by saying that she does not assume
events are simultaneously past, present, and future. For example, when Socrates was born in 470 B.C. his death was in the future. Later, at the moment when he drank the hemlock juice, Socrates’ death was the present. In A.D. 2005, however, Socrates’ death is in the past. McTaggart, however, has already anticipated a reply of this sort and has an ingenious rebuttal. The above response is trying to sidestep the issue by means of grammatical loophole. While it is employing grammatical tenses, it is stating a tenseless relational fact which is true at all times. Relative to 470 B.C., A.D. 2005 is in the future, always has been and always will be.

A is past to X and Y is future to X, if it is true, is true for all times. What McTaggart challenges the tensers is to show him how X can be past or present or future simpliciter without invoking the contradiction he has illuminated. Can one use tenses in an ontological sense to discuss Socrates’ birth and death without lapsing into logical contradictions? McTaggart believes he has definitively demonstrated that they cannot. Yet, while the aforementioned response is inadequate, an understanding of why it is inadequate does lead to an adequate defense of tenses.

A proper response to McTaggart must be one that is given in terms of tenses—ontologically, not just grammatically, must be about tenses and it must elucidate why tenses are coherent. If this is the criterion, though, then McTaggart’s argument against tensed time does not need a refutation as the objection against tenses dissolves upon a proper understanding of it.

Let us examine proposition 2:

[E]very event has [all three determinations]. If M is past, it has been present and future. If it is future, it will be present and past. If it is present, it has been future and will be past. Thus all the three incompatible determinations are predictable of each event, which is obvious inconsistent with their being incompatible…[4]

How exactly does McTaggart reach his conclusion that tenses are incoherent? In order for someone to reach this conclusion is necessary for him to look at tensed time from a tenseless perspective. McTaggart has imagined setting himself outside of time and supposes that time can be visualized in a linear fashion. Time, as McTaggart holds the tensers conceive of it, is a line upon which the ‘now’ of the present moves forward as the future beyond the present which in turn becomes the past:

Big Bang (time’s beginning)__________________‘Now’________ Future

direction of time’s arrow -->

In this, ironically, tenseless view of tensed time, McTaggart’s argument is indeed a fatal one—there is no escaping the conclusion that tenses are incoherent as each moment is in possession of all three tenses. Unfortunately for McTaggart, no tenser of any modicum of intelligence would accept this view of time. As stated earlier, proponents of the tensed theory of time hold that there is a radical difference between a moment being in the past as opposed to it being in the present or in the future. Time, maintain the tensers, is a dynamic and—if time must be represented linearly—this change is not just movement along the line, it is a change in the structure of the line.

The following diagrams are all possible ways to view tensed time that will be explained below:

Deterministic Enduring Present View:

Big Bang (time’s beginning)__________________‘Present’ ----------- Future

direction of time’s arrow -->

----------- Future

Indeterministic Enduring Present View: ----------- Future

Big Bang (time’s beginning)__________________‘Present’    ----------- Future
                                                                                            ----------- Future
          direction of time’s arrow -->                                           ----------- Future

Deterministic Postmodern View:

                                     ‘Present’ ----------- Future

          direction of time’s arrow -->

Indeterministic Postmodern View:

---------- Future

----------- Future

‘Present’ ----------- Future
----------- Future

----------- Future

direction of time’s arrow -->

Present and Future Tenses:

The future is something that is radically different from the past and present. Most non-philosophers, when speaking of the future, speak of the future as being open, as being indeterminate. The intelligibility of future tenses, however, does not depend upon indeterminism.

Let us assume that determinism is true and that from the moment of the big bang there was, has been, and will be only one physically possible future. Physical determinations ensured that it would be true, and could not be otherwise, that Socrates would be born in 470 B.C., would fight in the Peloponnesian War, and would ask philosophic questions that would eventually cause the Athenian state to force him to commit suicide. Now in this scenario, McTaggart’s linear description of time suddenly looks quite true. Even if we place ourselves within time, since it is true that the event of Socrates’ death was ensured from the moment of the big bang, it seemingly does possess all three tenses at once. Nevertheless, in a deterministic universe, however, there is an important difference between a deterministic present tense and what will become another deterministic present tense (i.e. what is the future).
            That which is present/now is present in two concomitant ways: it is
present in time and in existence. In A.D. 2005 (the present as of the writing of this paper)
George W. Bush is, unfortunately, president of the United States. George W. Bush exists
in 2005 and one of the aspects of his existence is the fact that he is president. Now given that the world is deterministic let us additionally hypothesize that I am Laplace’s demon and consequently, I know that in 2006 a woman by the name of Clair Jacqueline Anderson (later Clair Jacqueline Anderson-Clark) will be born in Ithaca, NY who will become president of the United States in 2042. Being the omniscient demon that I am, I know everything there is to know about both Bush and Anderson-Clark. Epistemologically, they are the same for me in that I know them both equally; however, ontologically there is an important difference: unlike President Bush, President Anderson-Clark does not exist here and now in 2005.
            In a deterministic universe the words ‘present’ and ‘now’ reference a particular
aspect of time’s flowing which is a necessary condition for an object’s existence.
Granted, the birth and presidency of Anderson-Clark are logical possibilities—ones that will come to pass due to physical necessity—but until the movement of time brings them into existence, they exist only as logical possibilities. This is the difference between the present and the future in the tensed theory. Present is actuality while future is possibility and only possibility. Thus, even in a deterministic universe no event can simultaneously have both the properties of being present and future. Given, however, that most contemporary physicists and all philosophical Libertarians hold that determinism is false, it is therefore necessary to examine future tenses in an indeterministic universe.
            When a tensed deterministic universe is incorrectly subjected to a tenseless view
it at first appears as if McTaggart’s argument is correct. It appears as if each event must
simultaneously possess all three tenses and as such the concept of tensed time is
incoherent. The same cannot be said about an indeterministic universe. If subjected to a
tenseless view, while prima facie it appears as if every event must be in possession of the
future tense, it is not the case that every event must be in possession of past and present
tenses. Allow me to illustrate. Let us assume Michael is juggling around twelve college names in his head and is considering which college to attend.[5] Each of these twelve colleges is a real and distinct possibility, each of them is a possible future for Michael, but until Michael choose one of them and actually goes there none of these twelve possible futures can be said to be anything other than a possible future because none of them is guaranteed to gain the actuality of existence that comes with existing in the present. Futurity cannot ever be predicated in an ontological way as being past or present.[6]

Past and Present Tenses:

There are many more ways to go about asserting the coherence of past and present tenses than there are with future tenses. As I see it, there are two legitimate ways of looking at the past and its relationship to the present. The two ways are mutually exclusive, but they are alike in that both assert that pastness is not a predicate of equal weight to presentness.

I. The Postmodern Approach

According to this view, there is no incoherence between past and present tenses since there are no past tenses simpliciter. Past tenses are merely semantic concepts that do not have corresponding ontological reality the way present tenses do.[7] The future consists of possibilities, the present is actualities, and the past is empty—it is nonexistent.

Prima facie, this view does appear a bit ludicrous. Without an objective existent past against which to judge, history texts are reduced to having the same validity as fantasy novels.

‘Did Frodo drop the ring of power into Mount Doom?’ This can be answered with a ‘no’ by reading The Return of the King and noting that, ultimately, the author has Gollum fall into the pit of lava with the ring rather than having Frodo throw it in. If the text says that that is how it happened, then that is all that is necessary for us to ascertain what form the reply should take.

‘Did Hitler conquer the world, and then get thrown into the sun by a giant purple space alien named Kal-El?’ Well, possibly yes, possibly no; it depends on the context of what one is reading and/or to the context of what one is referring. If one is reading a book that says Adolf Hitler conquered the world and was then hurled into the sun by an alien named Kal-El, then it is true. If, however, one is reading a book that says Hitler was defeated by the Allied forces and committed suicide in his underground bunker in spring of 1945, the statement about him being thrown into the sun by an alien is obviously false.

‘No. You’ve misunderstood me. I don’t want know what the books says happened, what to know what really happened. I want to know what is true outside of the books.’ In that case, I’m sorry my friend. You have asked for what is impossible. There is no objective truth existing out in the world by which we can judge states of history to be true or false. ‘So there is no objective true history?’ Correct.

In actuality, some philosophers who hold that the past is empty and that only the present exists, have come up with brilliant methods to ensure that at least some of the facts of history do have a real, objective existence. I do not seek to argue against or with them. Instead, I propose to give serious thought as to what the unreality of the past means for the discipline of history and for people in general.

In recent decades historians have come under heavy attack from the Postmodernists. Prioritizing language over experience, the Postmodernists regard “the human capacity to observe and interpret the world” with extreme skepticism.[8] Every reader of a text—be it primary or secondary—has “the pleasure of finding any meaning they like” in the text and this includes historians.[9] Every work created by a historian will include his or her own intentional and unintentional biases. An objective recreation and representation of the past is not possible. What then is history? As Michel Foucault put it, “There is no ‘history’ [rather there is] a multiple, overlapping, and interacting series of legitimate versus excluded histories.”[10] History is a form of information and it is a type of information that is used to legitimate existing institutions and power dynamics which in turn use their authority to support and legitimate the history that legitimates them while excluding as much as possible histories that question or attack them.

The above, of course, does not do justice to the depth and richness of the Postmodernists’ critique of history, but it should be enough for the reader to realize that the critique is quite scathing. What I think is truly interesting here is that if it is true that the past really is nonexistent, then the Postmodernists’ criticisms of history are right even if some or most of the epistemological reasons are wrong. This need not lead one to support the abolition of history as a profession. What it should require is a complete examination and revaluation of history’s function and who and what has benefited from that function and who and what has been harmed because of it.

The idea that the past is unreal may be unsettling for many people besides historians, but if it is true that the past is a construct made by historians to serve the purposes of certain individuals and certain institutions, and if, as it would necessarily follow, people’s individual pasts are psychological constructs, there is a marvelous potential. While it may not be easy, it is certainly possible to imagine that histories could be rewritten so as to produce the maximum benefit for all segments of society (perhaps this would include the creation of multiple histories for a single nation, perhaps not). Likewise, if it is true that our personality and even our memories are constructs built because of, and in response to, that which no longer exists and can no longer affect us, would it not be liberating to know that just as I have created myself, I can alter myself to be largely or perhaps even completely different? The last point is of course highly speculative, but it is an intriguing logical possibility that the non-reality of the past presents.

II. The Enduring Present Approach

Of course, it is certainly possible that the past does continue to exist. This is the approach I prefer.[11] As soon as this is admitted as a possibility, then comes the question: in what way does the past continue to exist, is it as real as the present or does it exist in a different way? If we are to take seriously the idea that the past continues to exist, we must adopt the former position and say that the past is just as real as the present. There is threefold reason for this. Firstly, granting the past existence but a type of existence that is different from the present seems to be adding an unnecessary additional category to one’s ontology. Unless there is a serious and legitimate reason for requiring two types of temporal existence, the positing of two is an unneeded complication. Secondly, and more importantly, if the past and the present are ontologically distinct and separate, one must ask how this distinction is to be made. In short, one must face McTaggart again.[12] Assuming that one can diffuse McTaggart’s attack, it becomes necessary to answer: I. what causes the ontological change from present to past? II. given that this change occurs, it makes sense to ask, when does it occur? i.e. how long does the present exist before it becomes the past? I see no non ad hoc way to answer either of these questions.

Assuming then that past and present are ontologically equal, are they still tensed? In regards to this question I must answer ‘no,’ at least in the narrower sense of tenses being more than semantic concepts and items of use. Past and present can indeed be spoken of in a tenseless manner in the sense that statements about what is past and what is present can be framed such that their truth values are changeless and eternal. This, however, does not in any-way illegitimate the use of tensed statements about the past and the present that we make use of everyday. Statements about the past and present need to be recognized as being contextual, as being token-reflexive i.e. self-referring. For example, when I say ‘I am currently sitting at a college computer writing an essay about time’ this statement will be true or will be false eternally in regards to the facts of the matter. While it is true that ‘present’ and ‘now’ do describe the structure of reality at that moment in the sense that they have truth values whereas statements about the future do not, it is also true that these words are indexicals like ‘here’ and ‘there’ that apply to where one is in time.

Past and present are differentiated from each other experientially. By ‘past’ I mean that which I am no longer experience as of this particularly instance in time i.e. the present. Being finite creatures, humans exist in only a part of the world and this part is both temporal and spatial. It is our experience of the world that constitutes what is present for us.[13] That which we are directly experiencing, be it mental activity or stimuli from the external world, is what which is present, and the moment it is no longer being experienced, it is past.

Someone may object and say that this subjective way of defining past and present is unsatisfactory. In response I say, yes, it is subjective, but I do not see this as problematic. It seems quite likely to me the origin of the concept of past and present as predicates applicable to time itself lies in individuals’ extrapolation and objectification of personal experience and conceptualization of what is past and what is present. I have never experienced being alive during the Reign of Terror nor can I experience it. I have experienced eating Thai food in high school for the first time and I have experienced my first kiss at college. While I remember both events, I am no longer experiencing either nor can I experience either again. In that I cannot experience living in Paris under Robspierre just as I cannot experience my first kiss again, I unite these two disparate facts under the category of being past.

At this point I imagine someone saying ‘You’ve been very convincing thus far and I am prepared to accept your analysis of past and present as legitimate provided you can explain to me why it is not possible for me to experience something in the past again—such as my own first kiss—or for the first time—such as being in Paris during the Reign of Terror.’ Fair enough. I will ask this objector to recall that the theory of time I am proposing and defending in this paper is ultimately a tensed theory of time, i.e. it is a theory that holds that time in some way flows and changes and that this flow has direction.

Why is it that I cannot experience the past? Because the flow of time directs me towards possibilities (or a singular possibility if determinism is true) that have not been actualized yet (and may perhaps not be actualized if indeterminism is true). In order for me to do anything it is necessary that I become the actualization of a possibility and possibilities are located in the future. I cannot experience actualities if I do not have possibilities of experiencing them that I can actualize. Time’s arrow points in only one direction—the future.[14]

A Note on Possibility, Actuality, and Potentiality

Whenever an object appears in a certain manner, it also has the potentiality, but not the actuality of appearing in other ways. An actuality is an existence that is formalized i.e. it has a definite form of being. The potentiality of an object exists concomitantly with the actuality of that object and it is of potentiality that once speaks of as being actualized.

Now what does a potentiality actualize to: a possibility. Possibilities of existence, ways that potentiality may be an actuality, are what gain or do not gain actuality through the actualization of potentiality. Possibilities do not exist concomitantly with the actuality of an object. Possibilities are ways things might be and they are in the future, not the past or the present. Potentiality, however, is that which exists in the present.

Let me give an example. A block of alabaster’s current form, its current actuality is that of being a block. The alabaster, however, has the potentiality of being something else. What else could the alabaster be? It could be a vase or a statuette. These possibilities, however, do not exist concomitantly with the actuality and the potentiality of the block of alabaster, they are future, not present. If I am a sculptor, of course I can conceive of the alabaster block taking the form of a vase while it is a block i.e. my conceptualization of the alabaster as a vase exists at the same time as the form of the alabaster is that of a block, however, the possibility of the alabaster being the vase is still in the future, not the present

Alabaster (Present): Possibilities (Future):

Block (the current form, the actuality) Vase

potentiality Statuette

[1] J. M. E. McTaggart “The Unreality of Time” Time Ed. Jonathan Westphal and Carl Levenson (Hackett Publishing Inc., 1993) Originally published in 1908, the audacity of the paper’s title comes from the fact that McTaggart felt that the very idea of time was equivalent with the idea of ontological tenses. Though I hardly share his conclusion, I do agree with McTaggart about the necessity of tenses for time. If tenses do not exist, time does not exist.

[5] It must be noted here that I am NOT assuming Libertarianism here. Michael’s brain processes could be largely deterministic but with just enough macroscopic indeterminism such that his cognizing is indeterminate albeit not under his control.

[6] And again I point out the important difference between understanding grammatical tenses and understanding ontological tenses. I could have said, ‘What is future cannot ever be predicated as being past or present.’ This a grammatical correct sentence, but if you look at it in an ontological way, it becomes tricky: how do I understand the phrase ‘What is future’?

[7] Rather appropriately, this view of time is often referred to as ‘Presentism.’ For readers who find this view of the past appealing, I recommend reading the works of Arthur Prior. I have also read that John Duns Scotus held a similar view, though I have yet to verify this.

[8] John Tosh The Pursuit of History 3^rd Ed. (London: Longman, 2002) 185

[10] Richard Appiganesi, Introducing Postmodernism 2^nd Ed. (Cambridge: Icon Books Ltd., 2002) 83

[11] I find this to be the more promising route for several reasons. The proper elucidation of why is a paper in itself, but I will say this much: I think the Postmodern approach is a conceptual absurdity as it renders all discourse and thought vacuous or potentially vacuous and renders BOTH determinism and Libertarianism absurd. The reader of course is free to disagree.

[12] In all honesty, I think that in terms of past simpliciter and present simpliciter, tensers must grant McTaggart victory. I see no way to opt for an ontological distinction between past and present that does not involve incoherence.

[13] Sometimes philosophers refer to what they call ‘the specious present’ when discussing our experience as our experience of what is present and how long something lasts may be different from is the ‘real’ present.

[14] Even if I manage to travel back in time so that I can experience events and objects that I would not be able to otherwise, time’s arrow will still be turned in the same direction. As for whether or not time travel is possible, that is something which goes beyond the scope of this essay.