Online research in philosophy

How can we talk meaningfully about the past if it does not exist to be talked about? What gives time its direction? Is time travel possible? This defence of presentism - the view that only the present exists - makes an original contribution to a fast growing and exciting debate.

In this paper I argue that presentism has a problem accounting forthe truth of statements whose truth conditions seem to require therebe relations that hold between present and non-present objects. Imotivate the problem and then examine several strategies for dealingwith the problem. I argue that no solution is forthcoming, and thispresents a prima facie problem for presentism.

Abstract: Presentism is the view that whatever exists presently exists. Without defending Presentism, I argue first that Presentists should be Time-Free Presentists – Presentists whose views do not imply that there exist irreducible times. Second, I argue that Presentists should accept Limited Thick Presentism, the view that 'the present' has some extension and is thereby neither durationlessly thin nor unlimitedly 'thick'. Third, before addressing several objections to Limited Time-Free Thick Presentism [LTFTP], I argue that defenders of LTFTP should accept that 'temporal becoming' involves an overlapping succession of present entities, not a 'skipping' from one set of present entities to the next discrete set.

It is, I think, possible to generate a variation of McTaggart’s (Mind 17:457–474, 1908 ) paradox that infects all extant versions of presentism. This is not to say that presentism is doomed to failure. There may be ways to modify presentism and I can’t anticipate all such modifications, here. For the purposes of the paper I’ll understand ‘presentism’ to be the view that for all x , x is present (cf. Crisp ( 2004 : 18)). It seems only right that, at a conference devoted to McTaggart’s work on time, we continue to pursue new ways in which his now infamous arguments remain relevant to us today.

There is a debate in the philosophy of time over the status of non-present entities. Do these things exist, and if so, what sorts of things are they? Recently, the debate has split into two groups, presentists and eternalists. Presentists hold that no past or future things exist now. Socrates does not now exist, though he did in the past; my future daughter does not now exist, though she may in the future. Ontologically, the present is distinct, serving to demarcate all that currently has existence. As far as the eternalist is concerned, all entities - whether past, present, or future - are equally real. If it was, is, or will be, it can be found in the eternalist picture of time. As such, there is no distinct present at which some entities exist while others do not; rather, everything enjoys the same ontological status. I will be concerned to offer an assessment of the presentist view. Common objections against presentism will be examined, amplified, and answered where appropriate. I will not examine the arguments in favor of the presentist view. Rather, I wish to describe why it is that the eternalist feels compelled to deny presentism. Ultimately, my goal will be to show that although presentism survives some of the current objections raised against it, it does not survive them all. Presentism is an interesting, but ultimately unsatisfactory view. There is a modified form of presentism (call it presentism*) that can meet the objections raised against the original position, and after noting some of the objections raised against presentism, I will sketch the outlines of presentism* in some detail. I intend to show that presentism* is able to retain what is most valuable about presentism, while also withstanding certain objections that the latter view could not.

In the present paper, I offer a new argument to show that presentism about time is incompatible with time travel. Time travel requires leaving the present, which, under presentism, contains all of reality. Therefore to leave the present moment is to leave reality entirely; i.e. to go out of existence. Presentist “time travel” is therefore best seen as a form of suicide, not as a mode of transportation. Eternalists about time do not face the same difficulty, and time travel is compossible with eternalism.

I argue that relations between non-identical times, such as the relations, earlier than, later than, or 10 seconds apart, involve contradiction, and only co-temporal relations are non-contradictory, which would leave presentism the only non-contradictory theory of time. The arguments I present are arguments that I have not seen in the literature.

I set out and evaluate several solutions to the grounding problem for presentism.

When pondering the relation of existence to time one often finds oneself with intriguing intuitions expressed with slogans such as ‘Only the present really exists’, ‘Present entities are more real than past or future entities’, and ‘The future is yet to be; the past is no more’. When we express these intuitions, we don’t seem to be saying, in a straightforward way, that past objects such as a recently popped soap bubble are merely no longer present. Instead, we seem to be voicing some philosophically important view regarding how existence and time are related. The view is presentism, but the slogans only vaguely suggest some view; they do not, by themselves, adequately express it.

I will argue that there are two philosophically important kinds of presentism, ontological and logical. Roughly put, ontological presentism is the claim that there is an objective ontological distinction between present and non-present entities: whereas a spatial change from here to there does not mark an ontological distinction, a temporal change from now to then does mark an ontological distinction. Waiving subtleties, logical presentism is the claim that we never quantify over past or future entities. On the face of it, the two theses seem pretty different. One concerns existence; the other, logic. I think we have failed to make significant progress in evaluating presentism because we have failed to carefully distinguish the two theses. In this essay I clarify, distinguish, and evaluate them.