As I intend to write my M.Litt. dissertation on the philosophy of time and temporal passage, I thought it might be useful to set down a few preliminary remarks concerning some of the points at issue, as well as some possible strategies for resolving them. So here goes…

In general, much discussion in the philosophy of time centres upon the following basic questions:

1. 1.What is time?
   

2. 2.Do the past and the future exist, or only the present?
   

3. 3.Does time really pass, or is temporal passage some kind of illusion?
   

4. 4.What makes statements concerning past and future events true?
   

Having already had one or two stabs at (1), I would like to focus primarily upon (3), which will also involve elements of (2) and (4), as all four questions are closely related. For example, if in answer to (2), one holds that both past and future exist, then question (4) concerning truthmakers for past and future events may be answered in exactly the same manner as it is for present events: namely, its being the case that something is thus and so (to borrow a McDowellian phrase) at the relevant temporal ‘location’. The converse view, known as presentism, however, takes it that only what is present exists, or is real, and so whatever makes statements concerning the past and future true or false must be something that is present, e.g. the traces or potentialities of the relevant events that currently exist, or else some fact about the world as a whole, e.g. that it is a world in which the sun came up this morning (what Robin Le Poidevin somewhat mischievously calls a ‘Bigelow property’). A third possibility is to deny, as per Merricks (2007), that such facts even require truthmakers, which is an option I plan to investigate in greater detail over the next few days.

It is notable that each of the above questions concerns what really is the case, as opposed to how things seem to us; i.e. they are explicitly metaphysical or ontological in character, rather than primarily epistemological or linguistic. This raises the question of how such issues can be decided in the absence of compelling phenomenological or empirical evidence for one account or another. Regarding (3), for example, whilst we clearly experience time as passing in the sense that things change in an apparently ordered and directed manner (the so-called anisotropy of time), and the same sentence uttered at different times may vary in truth value etc., whether this is admissible as evidence that time really changes as opposed to merely seeming to do so is something of a moot point. At the very least, the anti-realist about temporal passage owes us an account of why it seems to us that time passes, since the nature of temporal experience constitute at least prima facie evidence for the reality of temporal passage, but it is difficult to see how phenomenological or empirical evidence alone can settle the matter.

Such difficulties are compounded by the fact that all sides agree on most (all?) of the relevant data. It is, for example, true that today is 23rd June, that the Battle of Hastings took place in 1066, and that the sun will (presumably) come up tomorrow. It is also true that the future follows the present, and that the present follows the past, and that Ken Livingston was mayor of London before (hard to believe though this is) Boris Johnson. The truth of such tensed statements can easily be admitted by the presentist, four-dimensionalist and growing block theorist alike. The difference between these positions concerns, rather, what makes it true that these things are the case, or whether other unknown (or unknowable) facts the truth or falsity of which we are (presently) unaware have determinate truth values. Such issues are not something that can be resolved by turning to the contents of experience, temporal or otherwise. They can only be settled by application of familiar philosophical tools such as conceptual analysis designed to bring out paradoxes and contradiction, or by theoretical concerns such as simplicity, elegance, consistency with everyday thought and language. Even worse, such concerns often pull in opposing directions and are themselves subject to dispute. (Witness, for example, the disagreement over the role that intuitions should play in the philosophy of mind and language.)

In constructing a theory of time, as with theories of truth or modality, it is tempting to extrapolate from the ‘best’ case in which the relevant facts are known or easily accessible to us. In doing so, we construct a picture in which all of the facts are ‘stretched out in front of us’ such that were we to obtain appropriate access to them by means of empirical investigation, or by some benevolent deity, for example, then they would turn out to be of no different in kind to the everyday facts with which we are all familiar. Facts, one might say, are homogenous — even those to which we currently have, or could have, no access whatsoever, and which to all intents and purposes may not even exist without it making the slightest jot of difference to our present (i.e. actual) situation. One alternative to this Tractarian view is that in which the facts are somehow tied to our epistemic situation. It could be, for example, that we construct the facts by being in possession of appropriate concepts and ways of knowing, or that truth is itself ‘gappy’ in that certain regions of reality are genuinely indeterminate, not just because we have limited access to them, but because that’s really how things are. Such indeterminacy tends to offend our intellectual sensibilities since it introduces an additional outcome over and above the basic binary opposition of truth and falsity with which we are most comfortable. However, such a position cannot be ruled out of court without substantive argument (cf. Michael Dummett’s Truth and the Past).

In some cases, choice of theory may be dictated by more practical concerns, such as the theory’s ability to make predictions, or our ability to perform the necessary calculations — in fundamental physics, for example — or by mere simplicity of expression. Of course, it is generally desirable to avoid an overly anthropocentric view in which truth and falsity only applies to what can be known by us, or those beings sufficiently similar to us, but as soon as we stray outside of such human concerns it becomes difficult to maintain a grip upon what the resulting concepts actually mean, and in what sense we are entitled to draw any conclusions from them at all, except perhaps upon purely logical grounds (see my 2007 for further discussion).

All of which serves to illustrate the problem: the supposedly conflicting philosophies of time only disagree upon points that everyday experience and speech are at best agnostic to, and which are at worst irrelevant to any practical concerns. It could even be the case that several different theories are internally consistent, each of which agrees upon all of the empirically and experientially available facts, but that disagree about what it is that makes them true; i.e. the answer to questions (2) to (4). In this case, the theory of time would be underdetermined by the evidence, making it largely a matter of faith or ontological preference which theory one adopts, as is so often the case in issues of metaphysics.

My own preference is to take the phenomenological evidence as a basis for further refinement and to construct a theory with the minimum number of additional ontological commitments which diverges as little as possible from the ordinary ‘common-sense’ view embedded in everyday thought and language. Such evidence is perhaps the best we can hope for in any philosophical theory and is (I contend) most likely to maintain consistency with other widely held beliefs, such as those concerning reality in general or the mind (although it is conceivable that common-sense is inconsistent on these issues, in which case we may be forced to decide which of our intuitions we are most willing to reject). Such a theory should certainly be consistent with the best available physical theories, but neither can this factor be considered decisive since such theories are well known to be incomplete and conflict with each other on many important points — especially when it comes to issues of space and time (general relativity and quantum mechanics being an obvious case in point).

Whilst it is difficult, perhaps impossible, to draw any firm conclusions concerning the metaphysics of time based upon the phenomenology of temporal passage — or even of experience more generally — alone, an approach that involves a consideration of mental phenomena may perhaps prove more decisive. Thought, memory, consciousness, perception, etc. are all phenomena which take place ‘in time’, and whose essence, in a peculiar sense, particularly in the case of thought and memory, is time, as Kant and Heidegger, amongst others, have noted. Could it be possible to argue for or against particular theories of time based upon their implications for any explanation of such phenomena? Such a project would undoubtedly be complicated by the fact that there are no uncontested accounts of the phenomena in question, which are equally in dispute, and so any doubts that they cast upon a particular theory might equally be levelled at the account of the relevant phenomena, rather than towards the theory of time itself. However, this is certainly something that I would like to investigate further, and one upon which I hope to blog upon further in the relatively near future (if indeed, there is any such thing!).

In the mean time (!), I still maintain that a metaphysics of time based upon a dynamic, ever-changing present in which past and future supervene upon present reality or being, is the most plausible option, and will be seeking to develop and refine some form of presentism to overcome many of the difficulties associated with this doctrine in all its various incarnations. Perhaps the worst of these is the so-called truthmaker problem, as sketched out above. If Merricks is right, however, then this might, as with so many other philosophical problems, turn out to be illusory — unlike the passage of time or temporal becoming, which is surely a genuine feature of reality, regardless of what Einstein’s theory of special relativity, or naïve philosophical interpretations of it, might have to say about it!