Friday, July 25, 2008

Quick Thoughts on Some Remarks by Dummett

So I decided to read Michael Dummett's Truth and the Past to see if there was anything relevant for my dissertation. I suppose some of it may be, but I want to focus on some of the things he says in his penultimate chapter, "The Metaphysics of Time". Some of his arguments or considerations offered in this chapter are particularly weak or bordering on the question-begging (although, to be fair, these were just a series of lectures that have now been published in book form, so the brevity of some of the discussions is perhaps a little understandable). Of the four-dimensional model of the universe (by which he seems to mean a strange version of a tenseless, perdurantist view), for instance, Dummett says:

The four-dimensional model [...] deprives the world we observe of genuine change; there is only that of our awareness as we travel into the future. The model is grounded on the conception of our consciousness as moving through the static four-dimensional reality along the temporal dimension.

Now, first of all, no one that I know of holds a view like this. This reads like some unholy combination of a tenseless physical world coupled with a tensed mental world or else a timeless physical world coupled with a temporal mental world. Either way, no tenseless, perdurantist view is going to own up to anything like this. But Dummet continues:

A proponent of the four-dimensional model may deny this. We are, he says, irregular four-dimensional tubes (or hypertubes), with the peculiarity that consciousness attaches to our temporal cross-sections. Nothing changes: it is just that our different temporal cross-sections are aware of different things.

This is better, but it is still question-begging - the variation of an object along its temporal dimension, on a tenseless, perdurantist view just is the changing of the object. The perdurantist does not repudiate change, they give an account of it. Dummett misses the point here entirely. He continues:

This image is misconceived. Consider a description of other hypertubes, whose axes lie along a spatial dimension. To us these would appear long, very short-lived objects; if we learned that a different consciousness attached to each segment of one of the tubes, we should regard them as strings of distinct creatures. But if we were told that a different consciousness attached to each cross-section of such a tube at an angle orthogonal to its axis, and that the different consciousnesses varied continuously, we could make nothing of this at all.

It's not clear who the "we" is here (Van Inwagen and Dummet perhaps?), for quite a few people seem to be able to make sense of such things. Such a thing may be impossible, but it certainly seems intelligible or conceivable in a pretty strong sense. As we will see elsewhere, Dummett seems to like to think that if some view is contrary to a deeply entrenched belief of his, it must be unintelligible. Forget the fact that lots of other people seem to find it the opposite - or even to find that the denial of the perdurantist view is unintelligible itself!

Another less than stellar paragraph comes a few pages later, where Dummett writes:

Why should truth be explained in terms of knowledge? The question is whether it is possible to swallow the conception of a reality existing in utter independence of its being apprehended. [...] My question is whether it is intelligible to suppose that the universe might have been devoid of sentient creatures throughout its existence. What would be the difference between the existence of such a universe and there being no universe at all? To express the question theologically, could God have created a universe devoid of sentient creatures throughout its existence? What would be the difference between God's creating such a universe and his merely conceiving of such a universe without bringing it into existence? What difference would its existence make? It seems to me that the existence of a universe from which sentience was perpetually absent is an unintelligible fantasy. What exists is what can be known to exist. What is true is what can be known to be true. Reality is the totality of what can be experienced by sentient creatures and what can be known by intelligent ones.

It's not really clear here why we should take any of this seriously at all. This is all not so much argument as much as dogmatic assertion of Dummett's own crazy views. Of course, if one is already completely convinced of an antirealist view and think that such a view is necessarily true, one will likely find the scenario discussed here unintelligible. But that shows absolutely nothing. I could also hold crazy views about other things such that a very plausible view will then seem to me to be unintelligible. But that doesn't make the latter fact any evidence for my view - rather, it presupposes it. This is a particular example of how, unchecked, some badly formed intuitions and a lot of stubborness can snowball and lead one into incredibly implausible views. After all, many people will find the impossibility of Dummett's scenario unintelligible. After all, we normally do not think that the existence of stars or the wider universe is somehow dependent on us. That seems just as crazy (more, in fact) as the denial of the reality of the past that Dummett is so eager to escape from.

And notice his rhetorical questions! Here's a good example of the sort of thing I tell undergraduates not to do - introduce rhetorical questions in the place of actual argumentation, particularly when your opponents may very well have an answer for you. In this case, it seems perfectly clear what the difference would be between the universe existing or not, or being created by God or merely conceived. If the universe exists, all sorts of properties are instantiated, there are events occurring, etc. You may as well ask what the difference would be between me existing and me not - obviously, if I did not exist, certain properties would not be instantiated nor would certain events occur had I not been around. But the answer for the existence or non-existence of the universe is exactly parallel. To deny this as Dummett does would make the existence of the external world dependent on us so that it is literally metaphysically impossible that the universe could have been destroyed or ended up in some state such that sentient life never happened. This seems, to say the least, rather implausible.

As for being created versus merely conceived, that also seems too plain to even deserve mention - if God merely conceives of something, it does not exist, whereas if he creates it then it does. And so the differences will be just those between existing and not existing (as for his "What difference would it make?", if it is asking something beyond this, I have no idea what it is or why it would be relevant). He says, "It seems to me that the existence of a universe from which sentience was perpetually absent is an unintelligible fantasy," but, on the contrary, it is his view that seems the unintelligible fantasy. He says, "What exists is what can be known to exist. What is true is what can be known to be true. Reality is the totality of what can be experienced by sentient creatures and what can be known by intelligent ones," but all this is perfectly compatible with realism - it is only incompatible if we make these out to be actual analyses, where the epistemic claim in each statement is analyzing the metaphysical one. But even if we accepted these statements, there seems no good reason to read them this way. After all, the right hand side contains what already appear on the left, thus making such analyses circular and hence no good in developing any kind of theory. But there seems no other option for a view like Dummett's. Dummett simply seems to be confused, like most antirealists, and to have canonized that confusion as dogma.

UPDATE (7/27/08): I've just discovered that an Anthony Rudd in a 1997 Phil Studies article entitled "Realism and Time" makes an argument against the B-theory of time very similar to that of Dummett's against 4Dism, with all the same horribly mistaken assumptions. Rudd's arguments in this piece are, to put it politely, quite weak.

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