At 04:56 PM 11/16/97 -0700, Garry DeWeese wrote:
>At 09:49 AM 11/11/1997 -0700, Don N Page wrote:
>
>>Since many of us now think that time is just an approximate concept that
>>applies only for part of our universe, I would be very loath to agree that
>God
>>is confined to time, because then He might exist only within part of the
>>universe.
>
>This may start to sound like a broken record, but I do not want to say that
>"God is confined to time." This seems to spatialize time, to treat it as
>some kind of "realm" which God inhabits. Rather, I would say that God is
>temporal, in that he experiences succession in his being. But that is just
>the way concrete beings are, whether physical or spiritual.
I think I see that perhaps Garry sees time as somewhat like causal
relations, whereas I do see it more like space. Since Garry writes below,
"metaphysical time (God's time) is necessary, since God himself is
necessary," perhaps he sees causality as necessary. I must admit that I do
tend to see causality as fairly basic (more basic in my view than time,
which I spatialize), since otherwise I would not understand the meaning of
the doctrine that God created the universe. And it is true that our
understanding of causality seems to be largely based on our experience of
time. So I can see that it might be fairly natural to consider time as well
as causality as fairly basic.
The discussion with Garry is making me wonder whether time is indeed
more like causality than I have believed. However, since I see time as
merely a contingent and approximate aspect of part of our physical universe, I
am led to wonder whether causality also might be just a contingent and
approximate aspect of part of our world.
>As to whether time applies only to part of the universe, I would like to
>hear more from you. If you are referring to singularities, then I would
>reply that they are on the boundary of space-time and not it. If you are
>refering to something else, please enlighten me.
I was referring not to singularities but to the claim I have heard from
string theorists, which I am not competent to evaluate, that string theory (or
Matrix theory, or whatever the theory is that used to be called string theory)
includes solutions with spacetime and also other solutions with no spacetime.
Although the relation between all the different solutions of string theory
is by no means clear (I think to anyone, but certainly not to me), I suspect
that in the ultimate string theory these solutions will correspond to
different components of the quantum state of the universe. If so, part of
this quantum state will give spacetime (in some approximation), and other
parts will give something without space or time at all.
>> [snip]
>> I am highly sceptical of the statement, "I think a sound argument can
>>be offered to the effect that no concrete entity can be timeless, where
>>"concrete" (as opposed to abstract) entity is understood as an entity
>which is
>>possible the terminus of a causal relation." Even for entities within this
>>universe, there are (partial) theories of quantum gravity (e.g.,
>superstring
>>theory) in which there can be entities that transcend time. An example
>would
>>be the quantum state of the universe. It is postulated to exist, and yet
>some
>>components of this state may not have any quantity that can be identified
>with
>>time, whereas in other components (such as ours), there are quantities that
>>behave approximately rather like our ordinary notions of time. Thus the
>>quantum state transcends time and in that sense can be considered to be
>>timeless, even though it may describe within itself what we call time.
>
>Well, this sounds impressive. But you need to make clear why you mean
>when you say that such things as superstrings or the quantum state of the
>universe can "transcend time." It seems that, conceptualy, temporal and
>timeless are exclusive and exhaustive categories, so I am not at all clear
>what you mean by something being in time and still transcending time and so
>being timeless. Any mathematical equation is timeless, and if by the
>quantum state of the universe you mean some immensely complex version of
>Schroedinger's equation, of course that is timeless. And any solution to
>it might "describe time" but it would not be time.
I would agree that the universe as a quantum state would be timeless,
but part of the state would be our spacetime, so in some sense the timeless
universe would include time. That is the sense in which I mean that it
transcends time: as a whole it is timeless, but it includes time within
itself.
>> The statement, "An even stronger argument concludes that *if* God is
>>timeless, then time must be static, not dynamic" is analogous to the
>conclusion
>>that *if* God is spaceless, then space must be homogeneous, not
>inhomogeneous,
>>or the conclusion that *if* God is temperatureless, then temperature must
>be
>>uniform, not variable. [snip]
>
>The analogy fails. If you hold that God is spaceless, then you need to
>explain how God can be omnipresent, or related to *all* of space (however
>it is constituted). This could not be done if all of space did not exist
>for him to be related to. Similarly, if God is timeless, then you need to
>explain how he can be related to *all* of time, and that can only be done
>if time is static or B-theoretic in nature, that is, if the future is real
>as well as the past and the present.
I agree that I was assuming the B-theory, which you say makes time
static. I suppose that I was slightly objecting to saying that time is
static in the B-theory, since even though all times exist in it, things are
different at different values of the time, and this I would regard as the
dynamic nature of the universe. It is analogous to saying that things are
different at different points of space, which is what makes the universe
inhomogeneous rather than homogeneous. So if "static" is analogous to
"homogeneous," I would deny that both are correct descriptions, but
presumably Garry means "static" in a different sense. Can you elucidate
what you mean by "static," Garry?
>> Saying, "if God is strongly immutable, then there can be no change in
>>his knowledge, and God could not know what time it is *now* (as that
>obviously
>>changes)," is analogous to saying concluding that God could not know what
>place
>>it is *here* or how hot it is at some *temperature*. Certainly there is
>not
>>any unique *now*, *here*, or *temperature* such that God knows only one
>value
>>for each, but God can know the situation at all existing times, places, and
>>temperatures.
>
>"Here" and "now" are indexicals and so are relative to the spatial and
>temporal position of the speaker. Temperature is not an indexical, so it
>is irrelevant.
I'm not clear why temperature cannot be an indexical like spatial
and temporal location. Certain things can occur at a given location, at a
given time, and at a given temperature. So it would seem to me that
location, time, temperature, and many other things can be conditions under
which other properties occur. In other words, I don't see anything magical
about time as an indexical.
>> It is true that time is such a basic part of our common knowledge of
>>the world that it is often hard to realize that it is most likely a
>contingent
>>part of our part of our universe and so presumably created by God if He
>indeed
>>created every contingent aspect of our universe.
>
>I too assume that the physical time of our universe is contingent, simply
>because our universe itself is contingent. But if God experiences
>succession in his being--if for example the members of the Trinity
>communicate or share their love in successive stages--then metaphysical
>time (God's time) is necessary, since God himself is necessary.
Of course, even if metaphysical time were necessary, there would be
the question of how time within our universe is related to it. In other words,
how does physical time relate to God's time, if it does at all?
>Garry DeWeese
Then at 05:07 PM 11/16/97 -0700, Garry DeWeese further wrote:
>At 12:30 AM 11/16/1997 -0700, Don Page wrote:
>> I, as a B-theorist, have enjoyed reading the discussion by Garry
>>DeWeese (Thu, 13 Nov 1997 09:09:16 -0700) as an A-theorist, since I don't
>>recall interacting much with anyone who believes in A-theory. (John Leslie
>>was here the past two days, and he was trying to explain to me that
>>A-theorists that also believe in radical indeterminacy would have the only
>>counter-argument that he considered viable against the smooth operation of
>>the doomsday argument, but since Leslie says he is a B-theorist, I can't
>>have expected him to have given me compelling reasons for believing in
>>A-theory, and he didn't.)
>
>What is the doomsday argument?
I sent something on this privately to Garry. But basically, it is
the argument, originally due to the physicist Brandon Carter and greatly
expanded by the philosopher John Leslie in such books as Universes and The
End of the World, that the end of human history might be expected to come
sooner than one might have thought, because otherwise we would be unusually
early in the human race (e.g., if it goes on at present or higher population
levels for many centuries, so the the number of people after us is much
greater than the number of people before us, which has been extimated at
50-100 billion).
>> I appreciate the information that "A-theorists believe that there is
>>an ontological (not merely epistemic) asymmetry between past and present, on
>>the one hand, and the future on the other. The past and the present are
>>real, while the future is not." However, I am slightly confused, since I
>>thought Leslie told me today that A-theorists believe the present exists but
>>neither the future nor the past. Are such people also A-theorists, or is
>>there actually yet a different name for those who believe that only the
>>present exists?
>
>There are, in fact, two versions of the A-theory. One is more commonly
>called "presentism," for it holds that only the present is real. Sometimes
>this is referred to as "temporal solipsism." The more prevalent version of
>the A-theory holds that both the past and the present are real, but the
>future is not.
>
>> I also appreciate the point that "The fundamental issue here is not
>>what can be known but what exists. There is always the danger of conflating
>>epistemic with ontological claims." But now I am curious as to what the
>>evidence is that leads an A-theorist to claim that the future does not
>>exist. Also, for an A-theorist who believes that the past as well as the
>>present exists, what is the evidence that the past exists but not the future?
>
>Well, it is just the A-theory itself which claims that the future is not
>real. If one is an A-theorist, then ipso facto one believes that there is
>the ontological asymmetry in question. If, however, you are asking what
>evidence or argument is there for the A-theory, see below.
I intended to ask what the argument is for the A-theory, so I'll
consider it below.
>> In Garry's later posting (Thu, 13 Nov 1997 09:18:07 -0700) on God
>>and time he states, "I think we absolutely must distinguish between
>>metaphysical time (God's time) and the measured time of the physical
>>universe. Even if we cannot do better than an operationalist notion of
>>physical time, we still are not forced to give up the idea of absolute
>>simultaneity." Similarly, in his posting of Fri, 14 Nov 1997 21:55:45 -0700
>>he notes, "Even if people persist in moving relativistically, it seems that
>>we only are forced to give up our knowledge of simultaneity, not the thing
>>itself." I think I agree that I don't see (at least yet) how to force an
>>A-theorist to give up the idea of absolute simultaneity, but I would like to
>>ask what the evidence is that there is any such thing. Also, of what use is
>>the idea if it can never be known?
>
>I suspect that behind this there is the shadow of operationalism, but I
>neeed to let you address that for yourself, Don. As a critical realist, I
>am content to admit that there are realities which we do not--and perhaps
>cannot in principle--know. I would be quite loath to adopt the
>pragmatist's approach either, and see truth as only that which I can use.
>I believe that there is an infinite number of true propositions which are
>of no "use" whatsoever.
There is probably at least a shadow of operationalism in my query,
but I would not object to postulating entities that we cannot know (at least
directly) or cannot use pragmatically, so long as they give a simpler picture
of reality that is consistent with what we do know. But if the entities just
complicate the picture and have absolutely no testable consequences, then I
would see no reason to postulate their existence.
>As to "evidence" that there is such a thing as absolute simultaneity, the
>evidence is that it is entailed by the A-theory, just as the evidence for
>many things in physics is that they are entailed by the best current theory
>(e.g. what is the evidence for 10- [or 23-] dimensional superstrings?). No
>experimental evidence is available at this time. Conceivably such evidence
>could become available, or a better theory could come along which would
>shed new light on the issue in question and allow is to redefine,
>reconceptualize, or abandon it.
In view of my paragraph above, is there any way in which absolute
simultaneity simplifies the picture or has any testable consequences? In
other words, does it have any explanatory power?
>> Perhaps a clue to a possible motivation for an A-theorist is given
>>by Garry's final words of his posting of Fri, 14 Nov 1997 21:56:12 -0700,
>>"If temporal becoming is not a real feature of the universe, but is only
>>psychological, then I believe that it is difficult to give any real meaning
>>to the notion of causation, let alone to escape the fatalist dilemma."
>>Since I myself don't find these supposed problems with the B-theory nearly
>>sufficient to cause me to adopt the A-theory, I am curious as to whether
>>there is any more positive evidence for the A-theory than this.
>
>While you have often spoken of "evidence" above, I should make it clear
>that a metaphysical theory will be supported by certain arguments, and will
>be evaluated by the strength of those arguments, as well as by its power to
>explain certain phenomena (not unlike scientific theories in this regard).
>
>I'll offer three lines of argument which support the A-theory. I will only
>offer a summary of the arguments here, for reasons of space (the summaries
>are long enough!):
>
>(1) Common linguistic practice, while not determinative of reality (as some
>postmoderns would say), certainly reflects reality. The use of tensed
>language is evidence that temporal becoming is real and that temporal
>indexicals cannot be reduced to tenseless language plus a token-reflexive
>reference to the time of the utterance. The A-theoretic statement, "A bomb
>will explode in the station five minutes from now" conveys information that
>the B-theoretic statement, "A bomb explodes in the station five minutes
>later than the time of this utterance" does not, for the first will
>certainly be action-guiding while the second will not be, unless
>accompanied by additional information about the time of the utterance and
>what time it is now, a A-determination. Furthermore, expressions such as
>"Thank goodness that's over!" uttered after, say, a root-canal, are
>incomprehensible if reduced to the B-theoretic expression "Thank goodness
>the time of this uterance is later than the time of the root canal." Such
>example could be multiplied. There are admittedly deep issues in the
>philosophy of language involved here, but the basic point is this: human
>thought and action depend inescapably upon tensed determinations. The
>ineliminability of tense in guiding our beliefs and actions explains why
>tense is so pervasive in common linguistic practice. I suggest that this
>is an argument for the conclusion that reality itself is tensed--that is,
>that time is dynamic (A-theoretic).
First, I might try to say what Sidney Coleman said on the final
episode of the TV series Stephen Hawking's universe, to the effect that our
language developed to handle our normal experience, and so we should not
expect it to handle all that we learn in science. (Coleman was referring to
quantum theory, but I could also take it as referring to time as the fourth
dimension that is inextricably linked up with space.)
Second, I don't see the difference between "A bomb will explode in
the station five minutes from now" and "A bomb explodes in the station five
minutes later than the time of this utterance," except that the latter sounds
very stilted. "Now" just means "the time of this utterance," at least in
B-theory. Anyone who hears the second utterance and understands it
presumably seeks, within five minutes of the time of the utterance, to leave
the station (assuming that the person does not want to be in the station
when the bomb explodes, etc.). "Thank goodness
the time of this utterance is later than the time of the root canal" also
seems to make sense to me, because it presumably implies that at the time of
this utterance, there is less pain than at the time of the root canal,
something for which the person at the time of the utterance is thankful.
(Of course, it also implies that at the time of the root canal, there is
more pain, and so one might ask why one should be thankful for that, but
maybe it just means that he or she is thankful that not all times are so
painful as the time of the root canal. In any case, it seems no worse than
saying, after learning that one had missed an airplane flight which
subsequently crashed, "Thank goodness I wasn't killed," which
also seems to imply that one is thankful that someone else was killed.)
>(2) An entity may persist in in time by enduring, in which case it is
>conceived as being wholly present at any time at which it exists, or by
>perduring, in which case it is conceived as being spread out through time,
>and only a part of it--a temporal part--is present at any time at which it
>exists. A strong argument can be made that only enduring entities exist in
>A-theoretic time, while only perduring entities exist in B-theoretic time.
>Another argument then establishes that consciousness is only possible for
>enduring entities. Hence, if persons are characterized by (among other
>things) persisting consciousness, then they are enduring things, and time
>is A-theoretic.
What is the argument that consciousness is only possible for
enduring entities? I suspect that I would be very sceptical of such an
argument. I certainly regard myself as perduring rather than enduring, and I
regard myself as conscious.
>(3) A pervasive part of human experience is that our experience is present
>tense. (Of course, my present-tense experience of seeing the sun is the
>experience of the sun as it was some 8 minutes ago; nevertheless, the
>experience per se is present.)
I agree.
>But according to the B-theory there is no
>present-tense.
There can be conscious experiences, each one of which is present
tense (at least relative to the same experience itself).
>Further, consider the class of experiences of mentally
>tokening a sequence, such as counting to 50 when playing hide-and-seek, or
>counting sheep to fall asleep, or mentally playing the score of a piano
>sonata, and so forth. Now whatever might be said about events in the
>external world, it does not seem possible to avoid the conclusion that I
>experience each successive member of the sequence as first future, in that
>I am at least tacitly aware of its "coming," then as present, and then as
>past ("I got past the D-flat minor diminished seventh chord this time!").
>My experience is of the successive passage of mental states, and is
>A-theoretic in nature. But isn't it open to the B-theorist to reply that
>my experience of the "passage" of these mental states is itself merely
>psychological and not reflective of any ontological reality? Yes, but
>only at the pain of infinite regress which does seem to be vicious, for the
>psychological states themselves pass in succession, and would need then
>ever-higher-order states to explain the apparent succession of the
>lower-order states.
I agree that many conscious perceptions, experiences or
psychological states (whatever one wishes to call them; I'm not making a
distinction between these terms) have contents that can be divided into a
perceived anticipation of the future, a perceived awareness of the present,
and a perceived memory of the past. Furthermore, a perception can even
contain a perceived memory of an event along with perceived older memories
of anticipating the event. However, I don't see that one would have to say the
psychological states themselves pass in succession. (In classical physics
one might have a theory of time in which those of a single conscious being are
ordered in time, but in quantum theory I don't think this is necessarily so.)
The psychological states could just exist, without necessarily "passing" or
even being ordered in time.
>One additional point should be made. If time is dynamic, we need a theory
>of time which explains its dynamic character as well as its direction. We
>need to be able to explain why time "flows" at all, and why it flows in the
>direection it does. A causal theory of time answers both questions. A
>realist theory of causation can explain why a state of affairs at time t
>can bring about another SOA at time t+1. And if formulated properly, a
>causal theory can rule out both causal loops and backward causation (the
>arguments are significantly different) as being metaphysically impossible,
>thus explaining the direction of time (a notable feature of a causal theory
>of time, since as we know by now, arguments from statistical thermodynamics
>have shown that entropy--which used to be everyone's favorite arrow of
>time--cannot do the job).
I'm not sure what you mean by time being "dynamic." I could say
that spacetime is dynamic in general relativity, since the metric obeys
Einstein's equations, but I'm a bit doubtful that that is what you mean. If
you did, one could just say that general relativity is the theory that makes
time dynamic. (Of course, this is almost certainly not the final theory of
time, not least because it does not take into account quantum theory.)
However, I'm not sure I would say that time "flows" in this theory, or that
it has any direction. The equations of motion of fields in spacetime imply
that there are correlations between the fields at one time and at another,
which is what we interpret as a causal relation, but this goes equally well
in either direction (future to past as well as past to future).
>> Since John Leslie told me there are plenty of respected A-theorists,
>>I am really just confessing my ignorance of what their arguments are, so now
>>I am taking the lazy man's approach (or am I trying to be more efficient?)
>>of trying to find what their arguments are without having to take the bother
>>of actually reading philosophy texts on what I have thought was a very
>>implausible view (especially if the past is supposed to exist but not the
>>future; saying that only the present and neither the future nor the past
>>exist seems more nearly plausible to me). So perhaps Garry can enlighten me.
>>
>> Don Page
>
>I doubt that there was any enlightenment above! ;^) Metaphysical arguments
>are not easy to abbreviate. I am disturbed by the fact that almost all
>cosmologists I know are B-theorists (like you and Leslie and Davies and
>Tipler and others), but at the end of the day, I think this is a
>philosophical and not a physical question. But I can recommend a couple of
>good texts, if you are interested! (And I am enjoying the discussion.)
Garry has certainly made it more clear (though not yet perfectly clear)
what A-theorists believe. The issue is indeed a philosophical rather than a
purely physical question, but what we have learned in
physics and cosmology can be evidence favoring one philosophical viewpoint
over another. My own understanding seems to lead me to favor strongly the
B-theory, but I will admit that I have not seriously considered the
arguments for A-theory, so that is a reason I appreciate this discussion.
(Even if Garry's arguments don't cause me to adopt A-theory, I do want to
see if I can answer them from within the context of B-theory, or else it
would show that there are some problems with B-theory that I don't understand.)
I would appreciate your recommendation of some good texts, though I
won't promise to read them :). I enjoy a direct discussion more!
>
>Garry DeWeese
>
Don Page