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Saturday, March 02, 2013

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Assumption: I am assuming that this discussion pertains to contingent concrete objects only.

If I understand Presentism correctly, it maintains that the unrestricted 'exists' is extensionally equivalent to the predicate 'presently exists'(within the framework of the above Assumption). Hence,

1. For every x; x exists iff x presently exists.
(1) entails:
1*. For every x, x does not exist iff x does not presently exist.

According to (1*), since Socrates does not presently exists, it follows that

2. Socrates does not exist.

And by the same reasoning, since Sherlock Holmes fails to presently exist, it follows that

3. Sherlock Holmes does not exist.

Two questions:

a. Isn't there a difference between (2) and (3)? How would a Presentist explain the difference?
b. The presentist holds that (2) is true. What makes it true?
Another way of putting question (b): What could be according to the Presentist the truth-maker of (2)? Not Socrates, since no such thing exists.

Suppose that e is caused by e*. According to our more or less standard notion of causality, the cause precedes the effect in time: so e* is prior to e. Let e be a present event. It follows that e* is in the past; hence by (1*), e* fails to exist. But then if e* does not exist, then what caused e?


Peter,

To avoid the problems that fictional discourse might raise, I would substitute a merely possible past individual for Sherlock Holmes. I too would like to know how the presentist would accommodate the distinction between Schopenhauer and his merely possible first-born son, Will.

As for causation, that is a stock puzzle for presentists. Suppose causation is a relation whose relata are events. Suppose further that c precedes e in time. If presentism is true, then when c exists e does not, and when e exists, c does not. Assuming that a relation holds only if all relata exist, then either presentism is false, or relations can hold even if it is not the case that all relata exist.

The presentist Craig Bourne denies that causation is a genuine transtemporal relation. See A Future for Presentism, Chapter 4, Oxford 2006.

In the view of the presentist, couldn't the difference lie in the fact that Schopenhauer did exist, whereas Will did not?

I think one can distinguish between two casual series - one ordered "per se" and the other ordered "per accidens. Something ordered per se is immediately dependent on its approximately first cause to cause x at any moment. Something ordered per accidens, on the other hand, would not be immediately dependent on its approximately first cause to cause y. I'd liken "past truths' to something that is ordered per accidens because it seems clear the present does not need the past to still exist in order to exist (at least according the presentist) but it does need the past to have acted as an efficient cause of the current state of affairs without requiring that this past still be a persisting cause. For example, a son is dependent on their father to be brought into existence but his continual existence need not require dependence on his father's continual existence.

If the father no longer exists, it is still necessary to explain just what put the son into existence in the first place. So it seems to me that ontologically, the effect would still require its cause in retrospect. That in itself seems to provide a sufficient grounds for predicating certain attributes to the father, namely his being an efficient cause (i.e, a father) of his son's existence. Even if the father and the son die, the son's son is the continual causal link to the past. Even if somehow we are incapable of determining that past, the past would still have a real effect on the present regardless of whether we have determinate knowlede of it. It's possible for the father and the son's bloodline to completley die off for example, but even if it is undectable to us, their existence will have had some effect on the present conditions of reality. Maybe all you have left is the memory of him passed on by friends, but this memory itself is a casual link of his prior existence because it is his existence that explains this current memory.

Bill, this clarifies matters a little. Let me know clarify the sense in which I am an anti-presentist. You say

1. "There are past and perhaps also future concreta that exist but do not exist now"

I would eliminate the qualification 'that exist', since it is already given by the 'there are' at the beginning of the sentence. This gives

2. There are past and perhaps also future concreta that do not exist now

'There are' has to be read tenselessly. Presumably you would not hold disagree that there are now such things? And do we even need the tenseless reading. How about

3. There were (and perhaps also will be) concreta that do not exist now ?

But we still have the word 'exist'. We can dispense with this by saying

4. There were (and perhaps also will be) concreta such that there are (now) no such concreta

This is surely true. There was such a person as Caesar, now there isn't. We could even eliminate the initial 'there were', to get

5. Some concreta were (or will be) such that there are (now) no such concreta.

This simplifies the formulation by (a) removing the word 'exists', and thus remove the temptation to distinguish between wide and narrow senses of existence. Everything is in terms of natural language quantifiers. And (b) all verbs are tensed. However the problem as I would like to formulate it is that while the natural language formulation above, using the natural language quantifier 'some', makes perfect sense and is surely true, the corresponding formalisation is false.

6. for some x, x is such that for some y, y was identical with x, but not for some z, z is identical with x

That is, 'there were some things such that there are no such things' is Moorean when expressed in English, but self-contradictory when formulated in predicate logic. In predicate logic, there has to be (now) something in the 'domain of quantification' in order for an existentially quantified proposition to be true. You can avoid this difficulty by distinguishing between a quantifier sense of exist and a predicate sense of exist, or by tenseless and tensed verbs (which really amounts to the same wide/narrow distinction). My point is that you can formulate sentences in natural language where no such distinctions are presupposed, and which cannot be translated into predicate logic.

David Brightly understands the point I am making pretty well. The existential quantifier requires a tense, but the problem is that modern formal logic doesn't allow it one, and so cannot translate many natural language propositions accurately.

In overall summary, I agree with anti-Presentism, formulated as I have formulated it. Any distinction between wide and narrow senses of 'exist' is irrelevant to the problem I am worried about.

Or (d) complain that it's not clear in the statements whether 'exists' is tensed or untensed? My guess would be (2) tensed, (3) untensed, (4) untensed, (5) untensed, (6) in defn of RP, tensed.

Bill,

I think you are right about avoiding complications distinctive of fictional discourse. Schopenhauer's possible first-born Will will do.
Interesting that someone would deny that causation is transtemporal. I wonder what he replaces it with.

Clarifying David's otherwise hard to follow point. Bill's argument is:

1. Various predicates (e.g., is remembered by some Bostonians) are true of Scollay Square.
2. Scollay Square does not exist now.
3. If x does not exist, then no predicate is true of x.
Therefore
4. Scollay Square exists. (From 1 and 3)
Therefore
5. Scollay Square exists but is not temporally present. (From 2 and 4)
Therefore
6. Restricted Presentism [Necessarily, only temporally present concreta exist] is false.

DB says "Or (d) complain that it's not clear in the statements whether 'exists' is tensed or untensed? My guess would be (2) tensed, (3) untensed, (4) untensed, (5) untensed, (6) in defn of RP, tensed."

But of course if the definition of RP involves a tensed 'exist', then the argument 1-6 is a fallacy of equivocation, no?

Ed,

"The existential quantifier requires a tense, but the problem is that modern formal logic doesn't allow it one, and so cannot translate many natural language propositions accurately."

This is not quite true. If your complaint is about Modern Formal Logic (including extensions to First-Order), then your complaint is inaccurate. First-Order quantification can be extended to a Tensed-Logic which can express your natural language sentences in two ways. You may add some temporal operators a' la Modal Logic or you can introduce new temporal predicates and extend the basic language to express temporal relations. Either way, your sentence is expressible.

Of course, merely pointing this out does not solve the issues about Presentism.

David,

In order to express the dispute between Presentist and Non-Presentist views we must accept at least initially the coherence of both a tensed version of exists (and its cognates) and un-tensed or unrestricted ones. We can then express Presentism along the lines Bill proposed or perhaps along the lines of (1) and (1*) which I have proposed in my previous comment.

O/w I have not idea how to even state either position.

More: why would a Presentist disagree with 'tenseless' use of the verb 'exist'? Let's define *exist as follows

(*) Something *exists iff (def) it existed in the past, or exists now, or will exist in the future

Where the three tenses are properly tensed, of course. Then presentist might agree that Caesar *exists (because Caesar existed) or that Antichrist *exists (because he/it will exist).

And so a presentist might agree that Scollay Square *exists but is not temporally present (because Scollay Square once existed). But he/she would not agree that Scollay Square exists. Yet only because he holds that Scollay Square does not exist now, which is surely trivially true.

It is not the possibility of a tenseless 'exist' that makes you a Presentist. Then what?

David thinks the 'exist in (RP) is tensed. Here is RP again:

Necessarily, only temporally present concreta exist.

If the 'exist' in (RP) is tensed, then (RP) is a tautology, not a substantive metaphysical thesis. For if 'exist' is tensed, then it is in the present tense, and (RP) boils down to: Necessarily, only what is present is present. Which is obvious. And it is obvious that it is obvious!

So (RP) has to be untensed (tenseless). What (RP) implies is that when something ceases to be present, it ceases to exist at all: it becomes nothing. Now that is not obvious. For it is not a contradiction to maintain that what ceases to be present exists (tenselessly) but is no longer present. If something ceases to exist (tensed), then it does not still exist (tensed) or continue to exist(tensed), but one could say, and I think Peter will say, that it exists (tenselessly).

Is that clear?

Hi Peter,

Yes, of course I accept the possible coherence of the two versions of exists. In fact I pretty much agree with Ed on how that coherence works. But I need to know which 'exists' is which!

Ed,

Thanks for the expansion! I suspect equivocation is where we are headed.

Bill,

Thank you. I take your point. Are my other guesses right?

Every use of 'exist' in my original argument is tenseless. So I don't think I am equivocating.

Can I be accused of begging the question by assuming that tenseless uses of 'exist' are meaningful?

One cannot formulate the issue that divides the presentist and the anti-presentist unless one can somehow abstract from the temporal perspective of the present moment. One has to be able to 'survey' time analogously as one can survey space.

There are places that are not here and there are times (and events and objects at those times) that are not now. The second independent clause is what the presentist denies.

So there seems to be a substantive issue here.

Bill:"So (RP) has to be untensed (tenseless)."

But as I've argued, if the untensed version simply means 'existed, exists or will exist', then RP is obviously false:

*Necessarily, only temporally present concreta exist, or existed or will exist.

It is false, for example, because it implies that anything which used to exist, still exists in the present. So we have the problem that the tensed formulation is trivially true, and one interpretation of the untensed is trivially false.

What is it that the R-presentist is supposed to be saying?

Ed writes, >>In overall summary, I agree with anti-Presentism, formulated as I have formulated it.<< He formulates it this way:

>>5. Some concreta were (or will be) such that there are (now) no such concreta.<<

The trouble with (5) -- if you want to call it 'trouble' -- is that it is not something we can reasonably disagree about. It is 'Moorean' as we say in the trade. (5) implies that some things no longer exist, which is surely true. To deny that would not be to advance a metaphysical thesis but to advertise oneself as lacking basic common sense or knowledge of English.

So I object to Ed's calling himself an anti-presentist. He is apparebtly abstaining from the presentist-antipresentist controversy and sticking with ordinary languge. It may be that Ed's view is that this dispute is a pseudo-problem to be avoided by reverting to ordinary language, and using the tenses we all know how to use. Maybe Ed is inclining in a Wittgensteinian direction.

Peter:"First-Order quantification can be extended to a Tensed-Logic which can express your natural language sentences in two ways. "

Can you expand on that a little, please? Unmodified predicate logic cannot even express 'there is no such thing as Caesar', for the sentence 'not for some x, x = Caesar' is necessarily false. What if we put a tense on the identity sign? OK, but if 'for some x, x was identical with Caesar' is true, that implies that something in the domain was identical to Caesar. And surely if it is (now) in the domain, and it was identical to Caesar, then it must (now) be identical to Caesar.

What Ed at 12:50 shows in a backhanded way is that 'x tenselessly exists' cannot be defined in terms of 'x existed or x exists (tensed) or x will exist.'

I agree with Bill that Ed's formulation (5) fails to capture the non-presentist position and for the very reasons he cites in his latest post.

I still do not see what is the problem with Bill's original formulation of RP in his original post or with mine ((1) or (2)). Could someone give me an argument what is wrong with either one of these ways of stating the Presentist's position.

David,

"Yes, of course I accept the possible coherence of the two versions of exists. In fact I pretty much agree with Ed on how that coherence works. But I need to know which 'exists' is which!"

So what is wrong with my

1. For every x; x exists iff x presently exists.

One might even construe 'presently exists' in (1) as a hyphenated predicate 'presently-exists' and now we are clear that the first 'exists' in (1) is un-tensed; the second restricted to the present, hence tensed. I shall ignore the semantic question as to how we understand 'presently-exists' based on a composition of its hyphenated parts.

The reference to (2) in my latest post should have been (1*), not (2).

Ed,

" Unmodified predicate logic cannot even express 'there is no such thing as Caesar',..."

By "unmodified" I assume you mean Standard First -Order Quantification Theory.

How about:

(x) ~ (x = Caesar).

or equivalently

~(Ex) (x = Caesar).

But of course this was not my point. The point is that there is such a thing as Tense Logic and it can express much that Standard First-Order cannot, including tensed sentences etc.

But this is neither here nor there. What exactly is your problem with Bill's formulation of Presentism in his original post or mine as in (1) or (1*) above? Perhaps if you state it we can discuss your concerns. So far I am lost what precisely is your concerns.

Bill,

I guessed that (2) 'Scollay Square does not exist now' was intended to be tensed because it contains the temporal qualifier 'now'. If our understanding of tenselessness derives from appreciating the timelessness of 'two plus two is four' then presumably the 'now' qualification makes no difference just as it makes no difference in 'two plus two is four now'. So (2) just says 'Scollay Square does not exist (untensed)' and we arrive at contradiction with (4). The remaining premise (5) which brings in presentism is superfluous. So I move to strategy (b): there is a fault in the reasoning.

Peter,

>> So what is wrong with...

Could we return to your question later? Your remark that 'the second [is] restricted to the present, hence tensed' seems inconsistent with Bill's reply that all his uses of exist, including his (2), are tenseless. See my immediately preceeding comment to Bill.

Ed,

Why do you think that '(x)~(x = Caesar)' is necessarily false? Looks contingently false to me.

David,

The issue is whether the 'exist' in (2) is tensed, not whether the whole sentence is. 'exists' (present tense)= 'exists (tenseless) now.'

(2) does not contradict (4). Both occurrences of 'exist' are tenseless.

I'm sorry, Bill, you have lost me. Are you saying that there is a distinction between 'two plus two is (tenseless) four' and 'two plus two is (tenseless) four now'?

David,

What I was suggesting was that a tenseless use of 'exist' can be tensed by adding 'now.' But that holds only for something that can have a temporal location.

You admit that there are spatrial locations. Why can't there also be temporal locations? Think of all the temporal locations in the actual world from the Big Bang on. If something is at one or more of these locations then it exists tenselessly. If it is also present, then we can say it exists (present tense).

We say that Hume is an empiricist even though Hume is long gone.

Thanks, Bill. I was going to ask you to give me a decision procedure for deciding the truth of untensed existence assertions given a putative History of the World. Your answer is just as effective and quicker! I am happy to think of time geometrically. It's been a remarkably productive idea. Your latest explanation leads me to think that 'X exists (untensed)' is equivalent to 'X existed (tensed) or X exists (tensed)', and this is indeed what I have been thinking all along. However, you appear to reject this suggestion (from Ed) in your (rather cryptic, if I may say so) comment of 01:33 PM . Will you perhaps say that these are extensionally equivalent but intensionally inequivalent? Or if they are extensionally inequivalent there should be an example that distinguishes them?

There's an awful lot of things flying about here (probably my fault). Let's stay with Peter's for the moment. Peter asks:

>>What exactly is your problem with Bill's formulation of Presentism in his original post or mine as in (1) or (1*) above? Perhaps if you state it we can discuss your concerns. So far I am lost what precisely is your concerns.

My concern with Bill's formulation is that it contains an undefined term, namely 'exist'. Bill's formulation is

(*Bill) Restricted Presentism: Necessarily, only temporally present concreta exist.

My problem with this, as already stated, is that if the 'exist' is tensed, then it is trivially true (Bill concedes this). But if it is not tensed, then we require a clear definition of what it means to be untensed. I offered 'exists, or used to exist, or will exist'. But (as Bill also concedes, see his post at 01:33), on this definition, RP comes out as trivially false (see my argument below). So Bill needs to give a definition that turns it into a substantive metaphysical claim.

The same problem applies to your definition, Peter. You give

(*Peter) For every x; x [tenselessly] exists iff x presently exists.

You say that the first 'exists' is untensed. Fine. But can you explain what the 'untensed' sense is please? If we construe it as 'exists, or used to exist, or will exist', then your formulation is false. It comes out as

For every x; (x exists, or used to exist, or will exist) iff x presently exists.

which is false given that we agree that some things used to exist but do not presently exist, and so some things (tenselessly) exist but do not presently exist.

You may disagree with my definition. But then it is up to you or Bill to give a definition that turns your formulation into substantive metaphysical theses. For my part, I can only understand 'untensed' propositions such as "Every triangle has three sides" as tensed disjunctions. I.e. necessarily every triangle that existed in the past had three sides, every triangle that exists now has three sides etc. What else would they mean?

Bill >>Why do you think that '(x)~(x = Caesar)' is necessarily false? Looks contingently false to me.

Well if we agree that necessarily ~Fa implies Ex ~Fx, then it is necessarily false, since it leads to a contradiction. However there are (non standard) logics where this is not the case, e.g. see http://plato.stanford.edu/entries/logic-free

Ed,

"You say that the first 'exists' is untensed. Fine. But can you explain what the 'untensed' sense is please?"

No! And for a very good reason. Any attempt to "define" the untensed concept of 'exist' at this juncture will require defining exist in terms that will be theoretically more loaded than our more common sense understanding and therefore require diverting the discussion away from our central topic in this thread.

Example:
Could you define without circularity the tensed use of exist as in 'existed' or 'now exist'?

And when you do, please make sure that you also define what 'now' means, and what 'speaker' means, and what 'assertion' means, and so on. And also make sure you do not use the term 'the time', because of course this phrase presupposes that we understand time which, ...well, of course, it takes us back to the current dispute about, what else, time.

Bill introduced a certain way of characterizing Presentism and this cannot be done unless we allow at least at this early stage some leeway regarding a pre-theoretical understanding of some of our terms. 'Exist' tenselessly is one such term. This procedure is not new and it has no alternative except closing off the possibility any philosophical inquiry.

Ed,
The statement

only temporally present concreta exist
contains two verbs. We should read it as
if a concretum exists then it is temporally present.
Reading both verbs as untensed and interpreting 'untensed' in your suggested way gets us to
if a concretum exists or existed then it is or was temporally present,
which is true.

My working hypothesis as the moment is that presentist and anti-presentist are saying the same thing. It's just that the presentist is more fastidious about tense.

David: "in your [Bills] (rather cryptic, if I may say so) comment of 01:33 PM"

I know exactly where he was coming from.

Peter,

I agree basically with what you say at 5:09. Ed is often coy, evasive, and cadgy. Like many analytic philosophers he likes to feign incomprehension as a way of indicating that he doesn't find something clear enough for his taste. I can't believe he has no idea what a tenseless use of 'exists' is.

Since he was once a student of theology, this example may help: Imagine 'God exists' or Deus est as written by Thomas Aquinas. The English sentence features a verb that is grammatically present-tensed. But as used by a Thomist the verb is intended to be taken tenselessly. This is because God is timelessly eternal: outside of time. The same holds for Platonica.

Ed may be cadgy, but what I meant to say is that he is cagey. Sometimes.

Of course, I have no problem entertaining an inquiry into the questions about the notion of existence, including the meaning of its untensed version. But that will be a slightly different topic. Right now we need to presuppose somethings and go as far as we can. I suppose this is a methodological matter pertaining to philosophical discourse; I hope we can agree on some things and proceed from there.

David @ 6:04: >>My working hypothesis as the moment is that presentist and anti-presentist are saying the same thing.<<

That's clearly wrong. What is not so clear is what exactly the presentist thesis is.

Let me introduce the following convention: a verb or copula enclosed within parentheses is to be read tenselessly. Thus, 'Peter is smoking and thinking that 7 + 5 (is) 12.' So you could think of '( )' as an operator that detenses a tensed verb or copula.

(RP) then looks like this: Only what is temporally present (exists).

And 'Only what is temporally present exists' is a tautology. For it is tautology that only what is temporally present exists at present. (RP, however, is not a tautology.

(RP) implies that past items do not (exist).

That is clearly different from saying that past items do (exist), as one sort of anti-presentist will maintain.

Surely, David, you see the difference!?

Morning Bill,

Yes, I see the difference. But I don't accept that the presentist asserts RP with tenseless verbs. I think he really is offering us a tautology. If the verbs in your original argument are taken as tenseful then the resulting contradiction shows that some premise is false and the one to choose is obviously (3) though we might lay the blame at an objectual understanding of predication. On the other hand, if we take the verbs as tenseless then RP turns out obviously false and (3) as highly plausible. RP doesn't have to be a substantial metaphysical thesis for us to look at the argument either way.

Tenseless predication is 'non-standard'. That's not to say it's inconsistent. I agree with Ed that how this new bit of language, '(verb)', is to work needs explaining in terms that we all understand, just as Robinson's non-standard real numbers or Lawvere's non-standard analysis are grounded in standard mathematical language. You ask us to think in terms of 'temporal locations'. That's no problem. Graphs with a time axis are a way of presenting all of time at once, as it were. You say

If something is [(is)?]at one or more of these locations then it exists tenselessly. If it is also present, then we can say it exists (present tense).
I take from this that 'x existed or x exists' is a sufficient condition for 'x (exists)'. If it's also a necessary condition then I think I have understood (exists), and I see no problem with it. Anti-presentism says no more or any less than presentism, it merely uses different language.

But I suspect you will say, No, tenselessness reaches aspects of reality that tensefulness cannot reach. It is the Heineken of language. So we have arrived at our methodological differences once again.

Ed,
Cryptic squared = Enigma

>>I think he really is offering us a tautology.<<

This will come as a great surprise to the numerous philosophers these days who are presentists. All that scribbling in defense of a miserable tautology?

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