Presentism and the cosmos

On Tues, Apr 5, 2011 at 16:28:56
Fred asked this question:

I've been thinking about presentism and the conditions of the cosmos. It is well known that when we look out into space we are looking backwards in time. If we look out far enough we will eventually see the big bang itself. Since this is true, even if I look out a fraction of a millimeter from my eye, what I am seeing is in the past. Even when I look at my body I am seeing it not as it is, but as it was. Thus everything that I perceive is not as it is, but as it was. If presentism is true, it seems everything I perceive does not exist. Really, only my mind exists and I am a solipsist. Is this argument sound?

I take it that the argument in question is that presentism entails solipsism. The argument, as you state it, is unsound. I will explain why. However, there is a link between a particular way of interpreting what the presentist means which connects with a particular way of interpreting what the solipsist means. And this is something I see as valuable and important. I will return to that question later.

What is presentism? The first thing we need to do in evaluating this doctrine is to forget all we know about physics. In the actual world, the best evidence we have points to Einsteinian Relativity being the correct description. Relativity is also (as it happens) a more elegant and simple theory because it is based on the principle the laws of physics remain constant in all frames of reference. There is no 'ether flow', as the Michelson-Morley experiment demonstrated. So you can imagine that Relativity would be the theory God chose, if there was a God and He had the choice. That's what Einstein believed. But it is still only a theory which, if true, is true as a matter of empirical fact, not logical or metaphysical necessity.

The point of this preamble is that the presentist is perfectly entitled to say that there is at this present moment — the only time that is really real — something happening on a planet circling some star in the Andromeda galaxy. Maybe, a philosopher seated at a computer answering a question about the theory of presentism. What you see, when you gaze up at the night sky is the Andromeda galaxy as it existed 2.5 million years ago. The Andromedan philosopher is beyond all possible knowledge, so far as you and I are concerned. But that is consistent with the truth of, 'An Andromedan philosopher is thinking about presentism at this present moment.'

The statement I have just expressed makes perfect sense in a Newtonian universe. There is a case for saying that it does not make sense in an Einsteinian universe, where there is no absolute defnition of simutaneity. Two events 'happen' at the same time or at different times, depending on the frame of reference. All that means, however, is that the Einsteinian physicist has no use for such a definition. It is not required in order to express the laws of physics. However, as Richard Swinburne argues in his book Space and Time, that does not refute the belief in absolute time. (Swinburne is a theist: so you might suspect he has a special interest in putting the case for an absolute present which is God's awareness of the current state of the universe.)

I don't feel that I have sufficient knowledge of physics to wade into this debate. But it is not necessary to do so because, as I said, we are only concerned with evaluating the the argument that presentism entails solipsism. In order to demonstrate that the argument is invalid, it suffices to show that there is a possible world where presentism is true and solipsism false. The possible world in which Newtonian physics is true, is a counterexample to the argument. Admittedly, it is somewhat difficult to believe in presentism if you also believe in Relativity — because in Relativity there is no such time as the present — but as I have indicated the point is at least arguable.

Up to now, I have been talking about presentism as you describe it, what I would term 'naive presentism'. However, there is a deeper question whether there may be some way to express what the naive presentist means which does not attempt to encroach on territory occupied by contemporary physics.

Michael Dummett in his seminal article, 'The Reality of the Past' (1969), puts the case for what he terms an 'anti-realist' theory of meaning, which rejects the intuitively plausible idea that we can take the truth condition of a statement like, 'It's sunny today in Sheffield', and use it to account for the meaning of 'It was sunny at this location exactly 1000,000 years ago.' In the course of his argument, he makes the observation that to be an anti-realist with respect to the past involves taking the reality of time seriously. A realist about the past, by contrast, is more drawn to the eternalist view of time, according to which there is no pre-eminent time which we call now. Every time is a 'now'.

I share the intuition that it is a fact — a metaphysical fact, if you like — that the time is now. In terms of John McTaggart's distinction between the A-series (past, present, future) and the B-series (the series of events ordered by the 'before and after' relation), I would describe myself as an A-theorist. You don't have to be a presentist in order to be an A-theorist. One alternative would be C.D. Broad's view that the past is real while the future is unreal. Aristotle held a similar view. The past has happened, that's a fact, while the future is still open, it hasn't been 'made' yet. Some would regard this as just plain common sense.

I'm more drawn to Dummett's view. There's no recording angel. The ripples of events die down, until not a trace remains. There are no immutable 'facts'. I would go further and state that there are no truths, period, not even truths about 'what is happening now'. There are merely the things we believe, or say that we know and 'hold to be true'. No-one is keeping score except ourselves.

But who is 'we'? I can't speak for Fred, the author of the question, or for the anonymous reader of this post. Each of us has our own unique perspective, our own unique point of view. At the same time, we can and indeed must keep score of one another's beliefs and assertions. I can't do this just for myself. Wittgenstein's argument about private language and 'meaning is use' — the main inspiration for Dummett's argument — implies the incoherence of solipsism. There is no statement I can make about my experience concerning which I can claim incorrigible certainty. I am not the ultimate authority on whether or not I am 'following a rule' for the use of a word.

Yet, just as there is a fact that the time is now, and not some other time, so, I would argue, is it a fact that I am the person writing this post, not Fred, not the anonymous reader. This is what I argued for in my book Naive Metaphysics. I call it the (partial) vindication of solipsism. The I-now is an ultimate fact, but it is not the only fact, for, if it were, then all these words would be meaningless and there would be nothing to do but wag my finger. The conditions for the possibility of meaning must obtain, and they are a 'fact' too.

I won't deny that this is all deeply mysterious. I don't go in for mystery-mongering, but I recognize a contradiction when I see one. I also recognize when we have no choice but to believe that a contradiction (I call it a 'metaphysical contradiction') can be true. (Or, 'can hold' as I don't believe in 'truth'.) You're welcome to come back at me and say that, in saying what I've said, I've given up any right to evaluate the validity or soundness of arguments. But I would turn that around. My view of metaphysics is eclectic, maximally permissive. There are no 'true' metaphysical theories and there are no 'false' ones either. I believe in what I see, and I 'see a truth' in presentism, even while I accept that presentism is not true.