Chris,
I think something was missed here, so just to be clear.
(Strict) presentism – only present objects exist.
3D (according to Markosian) – “According to The 4D View, temporally extended objects have temporal parts, temporal extension is perfectly analogous to spatial extension, and time is one of four dimensions that are on a par, at least with respect to the manner in which objects are spread out in space-time. On The 3D View, however, temporally extended objects do not have temporal parts, temporal extension is very different from spatial extension, and time is unique among the four dimensions of the world, at least with respect to the manner in which objects are spread out in space-time.”
What I do not see in this 3D view is any distinction between points in time based upon a privileged now that marches through time – so it seems neutral wrt Series A and B.
Your comment said “It seems pretty clear to me that non-presentist 3D'ism is the "commonsense" view, at least, when it comes to the past — Socrates "exists in the past" and we unproblematically refer to him.”
But this sounds like a Series A comment, where there is a past (and present and future). However 3D doesn’t imply Series A, though it might be congenial in some respects.
Anyway, the point I wanted to confirm it that there seems to be space for a weak presentist (or if you don’t like that phrase, call it ‘Series A’) position that (as I said in my mail) “would allow past and future objects to exist, but exist in different ways.” (It is not worth arguing about terms but I am reasonably sure I have read or heard this called presentist – which makes some sense as it acknowledge the present.) This 3D weak presentist/ series A position may be the "commonsense" view you talk about.
It also then follows that there is a Series B (I would like to say eternalist) 3D position, where we have a time index but no real past, present or future.
BTW the oddity I find with the Markosian description is this – “By contrast, on The 3D View, objects are to be thought of as three-dimensional things that are not made up of different temporal parts. On this view, an object at a time — Descartes in 1625, for example — is the same thing as the whole object — Descartes. Thus, according to The 3D View, the relation between Descartes in 1625 and Descartes in 1635 is the relation of identity: each one is just the same thing as Descartes.”
As a term, 3D or three-dimensional things seems to imply spatial dimensions, but ‘Descartes in 1625’ and ‘Descartes in 1635’ are identical, and he had a wider girth in 1635 (or was in a different part of the house/country), then spatially he does not seem to be identical – his spatial characteristics (his 3D characteristics?) are then clearly not identical. But Markosian says “on The 3D View, objects are to be thought of as three-dimensional things”. How can we think of them ‘three-dimensional things’ and also identical at different times? What sense does three-dimensional have here? Does it just mean capable of having spatial dimensions?
I would have thought something like “on The 3D View, objects are to be thought of as having a three-dimensional spatial extent with no temporal extent that can be different at different times” would be less confusing.
Regards,
Chris
From: Christopher Menzel [mailto:cmenzel@xxxxxxxx]
Sent: 27 January 2011 19:32
To: [ontolog-forum]
Cc: mail@xxxxxxxxxxxxxxxxxx
Subject: Re: [ontolog-forum] Presentism (was Re: Ontology of Rough Sets)
On Jan 27, 2011, at 12:58 PM, Chris Partridge wrote:
Is the issue here *strict* presentism?
(Where weak presentism would allow past and future objects to exist, but exist in different ways.)
No. The qualification "strict" adds nothing; I should have just said "presentist".
I was under the impression that presentism and standard 3D accounts fitted naturally together (for example, Markosian makes this point in the Stanford article, though I find some of his comments on 3D a bit odd.).
I think Markosian's point is simply that one must be a 3D'ist if one is a presentist, pretty much by definition. But one can certainly be a 3D'ist without being a presentist. Presentism is a very problematic (though, I admit, rather metaphysically appealing, for whatever that's worth) form of 3D'ism — see for example the three difficulties Markosian mentions briefly at the end of the section on presentism in his article.
That one of the attractions of a 3D view is that it supports a presentist stance.
Otherwise, I cannot make sense of your comment – copied below.
CM> This is actually a rather radical metaphysical doctrine that encounters very serious semantic roadblocks not encountered by the standard 3D and 4D views.
It seems pretty clear to me that non-presentist 3D'ism is the "commonsense" view, at least, when it comes to the past — Socrates "exists in the past" and we unproblematically refer to him. For the presentist, this is strictly false, as there is no such ontological property as "past existence" and hence no such thing as Socrates to refer to. But how, then, do we make any sense of such apparently unproblematic commonsense truths as "Socrates was a Greek philosopher"?
Presentism, by my lights, as an utter non-starter for the purposes of knowledge representation. There might be tortured ways for the presentist to make sense of claims about past and future entities, but if we're interested in building usable knowledge bases for information systems, regardless of where we come down on the 3D-vs-4D issue, we simply need to be "ontologically promiscuous" (to borrow from the title of a lovely (and important) paper by Jerry Hobbs) about past and future objects and refer to them and quantify over them liberally and unabashedly.
From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Christopher Menzel
Sent: 27 January 2011 18:31
To: [ontolog-forum]
Subject: Re: [ontolog-forum] Presentism (was Re: Ontology of Rough Sets)
On Jan 27, 2011, at 7:00 AM, Ronald Stamper wrote:
The only things deemed to exist in a presentist ontology (metaphysical sense) exist now. The present is no prison because we now have signs that stand for things we wish to know about in the past and future.
Actually, for the strict presentist, that is flatly false, because there are no "things…in the past and future" for our signs to refer to and for us to know about, for only presently existing things exist and things only exist now. This is actually a rather radical metaphysical doctrine that encounters very serious semantic roadblocks not encountered by the standard 3D and 4D views.
Presentism, I contend, provides a valuable discipline for engineers of information systems because that's the kind of world we deal with.
Seems to me that the world we deal with is the same regardless of one's metaphysical take on time. Be that as it may, might I suggest that the view you are actually arguing for is not presentism but rather the standard (and, I think most would agree, commonsense) 3-dimensionalist view that there is a distinguished, objective, ever changing present in virtue of which things are (at any present moment) genuinely present, past, or future?
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