## 1. Kinds of Change




A change is real if and only if it makes on its own a real difference
to the world. Real change is (roughly) change involved in causing
something, change an item is caused to undergo or change not
"logically parasitic" on change in other things. (These
"or"s are inclusive, not exclusive -- one change can
satisfy more than one clause of this account.) Smith's kicking me
involves changes in Smith. Kicking me makes on its own a real
difference in Smith. When Smith kicks me, I undergo various changes
which count as real, intuitively -- being kicked makes many real
differences in me. On the other hand, when I become shorter than Smith
because Smith grows, Smith changes really but I do not. Gaining height
makes a real difference in Smith, but Smith's gaining height doesn't
make a real difference in me. Rather, my becoming shorter than Smith
in this way is logically parasitic on Smith's growing. It is simply a
logical consequence of a real change in something else, not a real
change itself.




Coming at the notion another way, a change is real if and only if
there is an absolutely or "broadly logically" possible world in which
it is either the only event that occurs in an entire universe or else
the sum of all events in a universe, while a change is a
"logical parasite" if and only if this is not true of
it. Consider Smith's kicking me. This looks like it could be the only
occurrence in a universe. It is absolutely or "broadly logically"
possible that the universe simply sits there wholly static, then Smith
kicks me, then the universe winks out of existence before anything
else happens. But actually, when we look more carefully, we see that
in this case, the kick is not the only change. For it has parts which
are shorter or spatially smaller changes. In the kick, for instance,
Smith's leg first moves an inch, then another inch, etc., and each
movement consists spatially of discrete movements by various
muscles. The kick is not the only change, but in the odd universe I
described, it is the sum of all changes in a universe. No change with
parts can be the only change in a universe, strictly speaking. On the
other hand, it is not logically possible that my becoming shorter than
Smith in the way described occur alone or be a sum of all changes
occurring in a universe. For it to occur, Smith's growth must also
occur. And Smith's growth is not a part of it. So changes are real if
and only if they are logically independent events in the world's
history. If God cannot change really, then, nothing can so act on him
as to change him, his actions do not change him, and no change in God
could be the only event in a universe. If God cannot change really,
then if had there been nothing other than God, there would have been
no change at all, of any sort.




Intrinsic changes are changes like learning or expanding, which
(roughly) occur entirely within the changing item -- which could
occur if the universe ended at the item's "skin." Putting
this more carefully, an item *x* has a property *F*
intrinsically just if whether *x* is *F* is settled entirely
by the states of *x* and *x*'s proper parts (if any), and a
change is intrinsic just if its occurring consists entirely in a
thing's gaining or losing a property had intrinsically. Changes which
are not intrinsic are extrinsic. All changes in relations to other
things are extrinsic. For instance, if a dog moves to my left, I
become a man with a dog on his left. This does not take place wholly
within me; whether it occurs is not settled by my and my parts'
states. It also involves the dog, who exists outside me.




Extrinsic changes aren't "real" in the sense above. I
change extrinsically when a dog comes to be on my left. The dog does
not so act on me at to make me have it on my left: the dog does
nothing to me at all. And my becoming a man with a dog on his left
could not be the only event in a universe. For it to happen, a dog
must also move. But to say that extrinsic changes aren't
"real" in the above sense is not to say that they don't
occur. It is merely to classify them.




The classical and medieval authors who developed DDI did not operate
with an explicit classification of changes. But Anselm, for instance,
argues both that God is immutable and that His relations with other
things can change (Monologion 25) and Aquinas does the same (ST Ia 9
and 13, 7). So as they understand DDI, it lets God change
extrinsically. Suppose that at *t*, Quine begins to worship
God. Then at *t*, God comes to have a new relational property,
being-worshipped-by-Quine. This is clearly an extrinsic change, since
its occurring in God implies the existence of someone
"outside" God, namely Quine. God does not (let's say) do
anything to cause this. It's a matter of Quine's free will. Quine
doesn't do anything to God by worshiping him. And this change in God
is a logical parasite of the real changes in Quine which constitute
his beginning to worship God. It's not possible that becoming
worshipped by Quine be the only change in a universe. Quine's
beginning to worship must occur too if this one does. DDI thus lets
God become Quine-worshipped. It rules out only real and intrinsic
changes.




This raises a question: why do only real, intrinsic changes matter? It
would be silly to ascribe to friends of DDI some sort of pre-given
general antipathy against real, intrinsic change. Disliking such
change makes as little sense as disliking universal properties- and
while nominalists campaign endlessly against these, it is not because
they have emotional attitudes toward them. Like nominalists, DDI's
friends simply followed various specific arguments, discussed below,
where they seemed to lead. And they seemed to lead to a denial that
God can change really and intrinsically, but not to a denial of all
divine change *tout court*. The arguments which led
philosophers to exempt God from real, intrinsic change all had to do
with ways real, intrinsic change or being capable of it might make God
less perfect. It isn't plausible that extrinsic change or openness to
it could make something more or less perfect. I am exactly as
impressive a man with a dog on my left as I am without a dog on my
left, though the dog might improve the scene including me. And I am no
whit less impressive for being open to having a dog move nearby.


## 2. Immutability vs. Impassibility



DDI is sometimes conflated with the doctrine of divine
*impassibility*, which asserts that nothing external can affect
God -- that nothing external can cause God to be in any state, and in
particular can cause him to feel negative emotions like grief.
Actually, DDI neither implies nor is implied by divine impassibility.
Something could be impassible but mutable if it could change itself,
but nothing else could change or affect it. God could be immutable but
passible. For he could be changelessly aware of events outside himself
-- perhaps even caused to be aware of them by the events themselves --
and due to them changelessly feel such responsive emotions as grief.
But he would feel them without change, and so always feel them. If
temporal, such a God would grieve for us before, while and after we
suffer what he grieves for. There is nothing counter-intuitive in
this. It's standard theism to hold that God has full foreknowledge of
what is to befall us: he sees our pain before we feel it, not just
while we feel it, and so grieves it beforehand if He ever grieves it
at all. There would be no difference in the quality of God's grief
before and while the pain occurs. For were there anything about it He
did not know beforehand, the foreknowledge would not be full, and full
knowledge beforehand should elicit the same reaction as full knowledge
during. Likewise, it's standard theism to hold that God is
cognitively perfect. If he is so and exists in time, He has a past to
recall and so has perfect memory. If God perfectly remembers your
pain, it is as fresh for him years later as it was while it occurred,
and if he perfectly loves you, perhaps he never gets over it. So we
can make sense of unchanging grief; if God does grieve, we might well
expect it from a God with full foreknowledge, cognitive perfection and
a perfect affective nature. If He is timeless, an immutable but
passible God would just timelessly suffer for us -- responsively,
i.e., because of our pain. The case would be just as if God were
temporal, save that His knowledge would not be temporally located and
so would not literally involve either foreknowledge or memory. So
whether God is temporal or timeless, DDI implies nothing odd here. And
it need not "depersonalize" God as some feel impassibility
would.




Still, it is surprising that Western theists have held DDI. For
Western Scriptures seem to conflict with DDI. Some Scriptural texts
depict human sin as making God sadder than he was (e.g., Gen. 6:6),
then bringing God to new decisions, e.g., to flood the world.
According to *John*, "the Word became flesh"
(1:14), i.e., God took on a human nature he did not always have. So
Western theism's Scriptural roots seem to deny DDI. Yet by the first
century C.E., DDI was central to the main theory of God's nature,
"classical theism." In such "classical theist"
writers as Augustine and Aquinas, being immutable makes God
atemporally eternal (see e.g. Aquinas, ST Ia 9-10), and eternality is
God's distinctive mode of being. So DDI is at the roots of such
writers' understandings of God's nature. And though Scotus and Ockham
led a revolt against divine atemporality, they and their followers
maintained DDI, and it ruled the theological roost till the
19th century. So one wonders: what made DDI so attractive
for so long?


## 3. The Case for Immutability




For one thing, the Scriptural witness is not really so clearly on the
side of divine real intrinsic change. Much that Scripture says of God
is clearly metaphor. And it is not hard to show that Old Testament
texts which ascribe change to God could be speaking metaphorically. As
I note later, one can parse even the Incarnation in ways which avoid
divine real or intrinsic change. Standard Western theism clearly
excludes many sorts of change in God. Western theists deny that God
can begin or cease to be. If God cannot, He is immutable with respect
to existence. Nothing can gain or lose an essential property, for
nothing can fail to have such a property. For Western theists, God is
by nature a spirit, without body. If he is, God cannot change
physically -- he is physically immutable. So the Western God
could at most change mentally- in knowledge, will, or affect. Further,
Scripture amply supports the claim that God is perfect in knowledge,
will, and affect. This perfection seems to rule out many sorts of
mental change.




This is a broader topic than can be tackled here; instead, let us
examine a few examples involving God's knowledge. If perfect in
knowledge, God is all-knowing. If God learns something new, then
before learning it, he was not all-knowing. Even if the new fact
could not have been foreknown, if He did not know it, He did not know
all. But only free beings' future actions and what depends on these
are even
*prima facie* beyond God's foreknowledge, and Scripture is full
of claims that God foreknows free actions. If God's knowledge is
perfect and includes complete foreknowledge, there is a sort of fact
about which God's knowledge is complete and unchanging. Suppose that
today God knows that I will finish this article tomorrow and tomorrow
God knows that I *am* finishing the article. There is a fact
God knows both days, that on this particular day, referred to one day
as "tomorrow" and another as "today," I finish
the article. Such facts involve no real tense: they are
'tenseless' facts. If God has foreknowledge even of free
creaturely actions, he always knows all tenseless facts. It is a small
step indeed from divine perfection to necessary divine perfection. For
it is surely more perfect to be unable not to be perfect than to be
perfect but able not to be. Again, it is a small step from
foreknowledge to necessary foreknowledge: the latter would be more
perfect. (If knowledge must be "safe," i.e. secure against error in
varying conditions, one's knowledge in one respect better if it is
safer, and it is maximally safe only if it is the case that
necessarily, if *p*, one knows that *p*.) If God's
knowledge is necessarily perfect, His knowledge of tenseless fact is
immutable. In any possible world in which He knows a tenseless fact,
He always knows it, if He is necessarily omniscient. So it is not
possible that His knowledge of it change, though if there are possible
worlds in which it is not a fact, there are possible worlds in which
He never knows it. Similarly, if God is necessarily omniscient, He
immutably knows all necessary truths.




So God's knowledge of necessary truth and knowledge of tenseless
contingent truth looks to be unchangeable, given only a small step
beyond Scripture. We can take this a step further. The only sort of
knowledge we've left out so far is knowledge of tensed contingent
truths -- such truths as that tomorrow I *will* finish the
article or yesterday I *did* finish the article. If God always
knows the tenseless correlates of these truths -- e.g., that on
March 27, 2002, it is the case that I tenselessly-finish the article
on March 28, 2002 -- then the sheer passage of time accounts for all
changes in His contingent knowledge. For which tensed truth God knows
-- that I will finish, am finishing or did finish -- depends
simply on what time it is. So to speak, he never has to learn about
whether I finish on March 28; he merely has to learn where in time he
is in relation to March 28, and this tells him what tensed
propositions are true about my finishing. Thus one can make a case on
what are basically Scriptural grounds that God's knowledge changes at
most due to the bare passage of time.




So Scriptural considerations suggest a God at least much less
changeable than we in some respects. But the roots of the full DDI are
also philosophical. In thinking out their views of God's nature,
Western philosophers have largely filled out the concept of God by
ascribing to him the properties they thought he must have to count as
absolutely perfect. God's perfection seems to rule out many sorts of
change, as we've just seen. More general arguments from perfection
convinced classical theists that God cannot change in any way.




In Republic II (381b-c), Plato argued for the full DDI. He asserted
that a god is "the... best possible" in virtue and
beauty. Virtue is a perfection of mind. Beauty is a non-mental
perfection. So Plato's examples are probably meant to do duty for all
mental and non-mental perfections, i.e. all
perfections *simpliciter*. If a god is already the best
possible in these respects, Plato reasoned, a god cannot change for
the better. But being perfect includes being immune to change for the
worse -- too powerful to have it imposed without permission and
too good to permit it. Thus a god cannot improve or
deteriorate. Plato's argument had great historical influence. But it
overlooked the possibility of changes which neither better nor worsen.
If one first knows that it is 11:59:59 and then knows that it is
midnight, is one the better or the worse for it? If the best possible
state of mind includes omniscience, then perhaps it includes constant
change in respects which neither better nor worsen God, e.g., in what
precise time God knows it is. Perhaps changes to 'keep up
with' time are required by a constant perfection, his
omniscience. At 11:59:59 it is surely better to know that it is now
11:59:59, and then at midnight it is better to know that it is now
midnight. Plato's argument does not rule out such changes.




Aristotle also contributed to acceptance of the full DDI. For many
medieval theists accepted Aristotle's case for God's existence.
Aristotle's *Physics* reasoned that if change occurs, it has a
final source, an eternally unchanged changer. Aristotle's *De
Caelo* added that something is eternally unchanged only if
unchangeable. Later theists thought the role of first cause of change
too lofty not to be God's. Writers who took Aristotle's argument or its
descendants to prove God's existence found themselves committed to
DDI.


Augustine gave a powerful impetus to Christian acceptance of DDI.
As he saw it (De trinitate V, 2), a God who gave His very name as "I
am" and is perfect must be the perfect case of being. But what can
change, Augustine thought, is not a perfect case of being: it does not
have its being so securely that it cannot cease to be what it is.




Boethius' Consolation of Philosophy (V, 6) also played a role in DDI's
popularity. He held that being in time must involve at least two
things which are defects. For being temporal, as Boethius saw it,
entailed having past and future parts of one's life. Temporal beings
no longer live the past parts of their lives. They do not yet live the
future parts of their lives. Both things are defects, according to
Boethius. So if God is free of all defects, Boethius reasoned, then
God has no past or future. What has no past or future does not
change. For what changes goes from what it was to what it then was
going to be, and so has a past and a future. Hence, to Boethius,
perfection required changelessness. Necessary perfection -- is
better than contingent perfection, and so by perfect-being reasoning
is God's. If perfection requires changlessness, necessary perfection
requires being immutable. Now Boethius' reasoning requires at least
some cleaning up. For a life could be temporal but lack past or future
parts, if it was instantaneous. And if one's past or future are bad,
it is not obviously a bad thing not to be living them. But perhaps
Boethius' argument has some merit. For it would not be a perfection of
an individual to live for only a single temporal instant. Surely
longer would be better, at least if there was a good chance that the
longer existence would be overall good. And if God is truly perfect,
His life, cannot contain parts it is overall bad to live.




Boethius actually followed his reasoning about divine perfection to
the conclusion that God exists outside time by his very nature --
that God can't be temporal. For whatever has neither past nor future
is not located in time. But change requires existence in time. Suppose
that a turnip, aging, goes from fresh to spoiled. It also then goes
from fresh to not-fresh. So first "the turnip is fresh" is
true, then "it is not the case that the turnip is fresh"
is true. The two cannot be true at once. So things change only if they
exist at at least two distinct times. Hence, if God is necessarily
atemporal -- via *necessary* divine perfection -- God
is necessarily changeless, i.e. immutable. Anselm clearly picked
up Augustine's and Boethius' tie between perfect being and
immutability: he wrote in Monologion 28 that God alone exists in an
unqualified sense and perfectly and absolutely, whereas all other
things nearly do not exist at all... For because of his unchangeable
eternity, it can in no way be said of (Him) because of any alteration
that he existed or will exist; instead, he exists in an unqualified
sense. Nor does he exist changeably, so that he is now something that
at some time he was not or will not be. Nor does he fail to be now
what at some other time he was or will be. Rather, whatever he is, he
is once and for all, all at once, and illimitably. And since his
existence is like this, he is rightly said to exist in an unqualified
sense and absolutely and perfectly.




Aquinas (like Augustine) derived DDI from the deeper classical-theist
doctrine of divine simplicity (ST Ia 9). If God is simple, God has no
parts of any sort. Now when the turnip aged, it became partly
different -- its smell and texture altered. Were this not so, no
change would have occurred. But if the turnip had changed
in *every* respect, it would not have been a case of change
either. For it would have changed with respect to such properties
as *being a turnip* and *being identical with this
turnip*. And if first we have something identical with this turnip
and then we have something not identical with this turnip, the turnip
has not changed, but disappeared and been replaced by something
else. So whatever changes must stay partly the same (else there was
not change in one selfsame surviving thing). So only things with parts
or distinct aspects can change. If so, a simple God cannot
change. DDI's connection with divine simplicity and the classical
theist theory of God's perfection which centers on divine simplicity
is one of the deepest reasons for DDI's broad historical appeal; one
cannot fully explain what moved thinkers to accept DDI without also
treating the motivation for the doctrine of divine simplicity. That,
however, is too large a topic to broach here.



DDI, then, has a variety of religious and philosophical roots.


## 4. Arguments Against Immutability




There are many arguments against DDI. Al-Ghazali (The Incoherence of
the Philosophers, XIII) originated one that was re-invented by Norman
Kretzmann (1966). We can put a version of it this way:


1. If God is omniscient, God knows what time it is now.
2. What time it is now is constantly changing. So
3. What God knows is constantly changing. (First He knows that it is
now *t* and not now *t*+1, later He knows that it is now t+1
and not now t.) So
4. God is constantly changing.


(2) assumes that presentness is a metaphysically privileged status,
and what events, times or states of affairs have it is constantly
shifting: following current jargon, let us call views of time which
hold this A-theories. Kretzmann and others who push the argument
speak as if there were also a unique universal present, but this is
inessential: if due to relativity we were to say that there are
different nows in different places, an omniscient God would have to
know what time it is now at all of them. Some responses to the
argument deny this assumption: Helm (1988), for instance, suggests
that all temporal truths can be expressed by wholly tenseless
propositions, though he also notes that if one finds this
unacceptable, he would be content with the claim that for every tensed
proposition there is a tenseless one that reports the same fact.


(3) assumes that one knows that *p* only if one can truly
token "*p*" to oneself. Aquinas seems to have
questioned this. He reports "ancient nominalists" as
dealing with (1)-(4) by denying (3) -- they claimed that
what God knows is simply an event, the nativity of Christ, and so the
sentences "Christ was born" and "Christ will be
born" signify the same thing, since they signify the same event
(ST Ia 14, 15 ad 3), and therefore the objects of divine knowledge
these sentences express do not differ. Aquinas objects that the
differences in the sentences cause them to express different
propositions, and so concedes that it is not true that whatever
proposition ever expresses what God knows, always expresses what God
knows. This, however, does not mean that God's knowledge itself
changes, Thomas adds, because He does not know what He knows by
affirming propositions (ibid.). Rather, His knowledge is a timeless
intuition which shows that propositions are at one time true and
another false (ibid. et De Ver. 2, 5 ad 11; for commentary see
Sullivan 1991). Aquinas, then, might simply deny the tokening
requirement, and so (3): he may object not to the nominalist move, but
to how they get there.


 Hector-Neri Castaneda replied to Kretzmann by way of the claim that



> 
>  P. If *x* knows that *y* knows that *p*, *x*
>  knows that *p* (1967, 207).
> 


(P) is plausible. If *x* knows that *y* knows that
*p*, *x* knows that *p* is true, since knowledge
entails truth. But plausibly, if *x* knows that *p* is
true, *x* knows that *p*. Suppose, then, that our immutable
being is an atemporal God, seeing time from without. God knows that
Smith, at *t*, knows that it is now *t*. God knows that
Jones, at *t*+1, knows that it is now *t*+1. By (P), God
atemporally knows both propositions, without having to change --
though if we impose the tokening requirement, we have to add that He
can token them to Himself only through other sentences than "it
is now *t*" and "it is now *t*+1": for an
atemporal being cannot truly token either. Swinburne objects: (P) does
not just (say) predicate properties of an individual, but presents the
individual to *x* a particular way, and *y* does not know
what *x* does unless what *y* tokens to *y* presents
that individual to *y* the same way what *x* tokens to
*x* presents it to *x* (1993, 170-1). However, this reply
may equivocate on "what y knows." It is one thing for
*x* and *y* to know the same proposition, and another,
perhaps, for the proposition to have the same overall cognitive
significance for *x* and *y*. A mode of presentation might
affect overall significance without providing further information that
might be stated in a further proposition. Still, (P) is in fact
false. If God tells me that He knows the date of the Second Coming, I
know that God knows it: He cannot lie, and I know that He is
omniscient anyway. But I still do not know the day nor the hour.


 Edward Wierenga (1989, 175-90) offered two replies to the
argument, based on differing accounts of what propositions are
believed and the requirements of omniscience. On the first, an
omniscient being would know all truths, propositions expressed by
present-tensed sentences predicate properties of whatever time has a
time-haecceity *T*, but they and all other propositions are
eternally true. Knowers in time have access to the time
with *T*, and perhaps *T* itself, only at that time: so what
changes over time is not what is true, but what temporal believers
have access to. But (Wierenga notes) there is no reason to think that
an atemporal believer would suffer similar access limits. (After all,
plausibly it is being in time that imposes them.) So on this account
there is no bar to holding that an atemporal believer timelessly knows
the same truths temporal believers know only at some times. In
effect, Wierenga denies that (2) implies (3): if all truths are
eternally true, what is true does not change. Kvanvig 1986 had made a
broadly similar move.



William Craig has argued that this move is incompatible with an
A-theory of time (2001, 119-23). In a sense Wierenga need not
care. He was not aiming to show that omniscience, immutability and an
A-theory are compatible, but only that omniscience and immutability
are compatible. If the conjunction of omniscience, immutability and a
B-theory is consistent, its members are pairwise consistent, for if
there were a contradiction between any two conjuncts, the whole
conjunction would ipso facto be inconsistent. But in any case, Craig's
charge misfires. This first move is compatible with real passage.
The first move entails only that if time passes, passage is not
represented by first one thing and then another being true. Passage
is instead represented by something within the overall set of eternal
truths- perhaps something as simple as an assertion that time passes,
or even that each time, when present, is all there is to temporal
reality. Passage can also appear in our story as what explains change
in what we have access to and perhaps in the overall cognitive import
of our belief-states. Wierenga's view can allow that the times he
speaks of are A-theoretic, existing only when present. The view
requires not that times be tenselessly there but that their
haecceities be always and atemporally available.



On Wierenga's second move, there is no such thing as truth
simpliciter. Rather, all truth is truth at a perspective (a pair
<*S*, *t*> of a person and a time). If I am sitting
now but was not sitting at midnight, the second move does not say that
the proposition <I am sitting> first was not true and then was.
Rather, it says that <I am sitting> is true at <me, now>
but was false at <me, midnight>. Given this machinery, Wierenga
defines omniscience this way: *x* is omniscient just if for all
propositions *p* and perspectives <*S*, *t*>,
if *p* is true at <*S*, *t*>, *x* knows
this, and if *x* is at <*S*, *t*> and *p* is
true at <*S*, *t*>, *x* knows that *p*. With
these moves, it's easy to show that atemporal (and so immutable)
omniscience is possible if there can be such a thing as an atemporal
perspective. If so, those pushing (1)-(4) can rule out immutable
omniscience only if they can provide independent reason to think that
necessarily, all perspectives are temporal. If they have that, of
course, they do not need (1)-(4), because if God is temporal and
persists, His perspective changes and so what He must know to be
omniscient changes. Thus (1)-(4) turns out dialectically
impotent and otiose.


Craig claims that recourse to truth-at-a-perspective is
incompatible with an A-theory (2004, 107). This is so, he thinks,
because propositions true at *t* must be true simpliciter
when *t* is the unique objective present. But why think so? Here
is another A-theoretic view: when *t* is the unique objective
present, all temporal perspectives that actually exist
include *t*, truths indexed to t are true at all actually
existing perspectives, but there is no such thing as truth
simpliciter. Unless there is some hidden inconsistency here,
A-theories do not require truth simpliciter. Craig claims that
Wierenga's second move too is incompatible with an A-theory (2001,
2004). But on this move, omniscience does not require that
perspectives be tenselessly there. It requires that propositions
about them be always and perhaps atemporally available, which one can
assure by taking "*t*" as shorthand for "some time with
haecceity *T*" and letting haecceities exist necessarily.


The second move works given an A-theory, but has a consequence
A-theorists may not like. Suppose that time really passes: indeed,
suppose presentism, on which only the fleeting present is real. Then
first <it is now *t*> is true at those temporal
perspectives that include *t* (on presentism, there are no
others) and then it is false at all perspectives (on presentism,
since *t* is now past, there are only temporal perspectives in
which it is false). But at an atemporal perspective, it is never true
that it is now *t*, for any *t*. There is no time it is in
eternity; if there were, eternality would not be an atemporal mode of
being. So at an atemporal perspective, time simply does not pass,
there is nothing about passage to know, and this is why passage poses
no problem for immutable omniscience. Passage is real in time, then,
but not at an atemporal perspective. Requiring an atemporal being to
know that it is now noon to count as omniscient is like requiring
someone at midnight to know that it is now noon to count as
omniscient: what is not true at one's perspective is not knowable then
either.


Of course, one wants to know how to make sense of the idea that
passage is real only in time. Stump and Kretzmann (1981) gave a take
on this while retracting Kretzmann's original commitment to
(1)-(4). Suppose presentism. On the Stump-Kretzmann picture,
each time t, when present, is "ET-simultaneous" with the life of an
eternal being. So that life is ET-simultaneous with t. So all times,
precisely in their presentness, are just ET-simultaneous with an
eternal life. But in an eternal life, nothing passes. If it did, that
life would have earlier and later parts: it would be temporal, not
eternal. So in God's eternal life, each time, precisely in its
presentness, remains: nothing ever ceases to be ET-simultaneous with
God's life, for that would entail an earlier and a later simultaneous
to God's life, and so in God's life. So while times pass in time,
they do not pass relative to eternity. Leftow (1991) offers a broadly
similar picture, but works with a differently-defined
simultaneity-relation.



Kretzmann's argument is simply that an omniscient being must be
"subject to change" (1966, 410): he does not sort changes as intrinsic
and extrinsic. One of his examples of change induced by a change in
what is known is clearly an extrinsic change (1966, 411).




So one reply is that knowing the correct time is not an intrinsic
state of God's, and so change with respect to it would not contradict
DDI. Intrinsic states are those settled entirely within one's own
skin. But then unless *p* is a truth entirely about matters
within one's own skin, knowing that *p* is not an intrinsic
state. For that one knows that *p* rather than believes falsely
that *p* only if *p* is true, and if *p* is not a
truth entirely about matters within one's own skin, whether *p*
is true is at least partly settled by matters outside one's own skin.
But when it is now is not a matter settled within God's own skin. What
time it is now is not a fact about God alone. It is a fact about time,
which is not God, and also about the entire temporal
universe. Further, it arguably is not the case even that what is
within God's skin settles what time it is in the sense that were
nothing else than God to exist, facts about God would suffice to
determine what time it is. For this would be at best a contentious
claim, as it implies that God would be in time if he existed alone,
without a universe. Many would say that time is an aspect of the
physical universe -- no universe, no time either. Moreover, even
if God existed alone and were then in time, knowing what time it is
would not be a *temporally* intrinsic matter. God knows that it
is now *t* just at *t*. So knowing the correct time
at *t* is temporally intrinsic only if it does not entail the
existence or occurrence of anything that exists at other times. But
for any time after the first instant (if there was one), knowing what
time it is involves knowing the temporal distance between the present
time and some other time: knowing that it is noon, April 16, 2002,
implies knowing a relation between that time and date and the date
traditionally assigned to the birth of Christ. Thus knowing what time
it is entails knowing that there was some time other than the present
-- a time outside the period in which God knows that it is now
this time. Knowing what time it is at any time after the first instant
thus is not a temporally intrinsic state. And if this is so, it is
hard to see why even knowledge that it is time's first instant would
be. Thus the objection has a false premise. If God's cognitive state
with respect to what time it is changed, it would not follow from this
that he is not *intrinsically* immutable. This result may seem
a bit hard to swallow. One wants to know *how* a change in
knowledge could fail to be an intrinsic change. One answer might
appeal to externalist theories of mental content. On these, my
knowledge that *p* is a complex consisting of my inner mental
state plus certain items in the world. Perhaps God's knowledge that it
is now *t* is something like a complex consisting of God's
inner cognitive state and an external component, *t*. If it is,
perhaps the only change involved when God first knows that it is now
*t* and then knows that it is now *t*\* (> *t*)
is the change from *t* to *t*\*.




Other arguments against DDI appeal to Scripture's depiction of God
as changing, e.g., in the Flood story. Facing such texts, DDI's friends
defuse the appearance of divine change by appeal to doctrines less
speculative and theoretical than DDI. Thus Philo argues from God's
foreknowledge of the future and constancy of character that God cannot
repent or feel regret, as the Flood story suggests. The Incarnation is
an especially knotty problem for DDI's Christian friends. In general,
these argue that all change it involved occurred in the human nature
God the Son assumed rather than in God; God was eternally ready to be
incarnate, and eternally had those experiences of the earthly Christ
which the Incarnation makes part of his life. Through changes in Mary
and the infant she bore, what was eternally in God eventually took
place on earth.




Another argument against DDI appeals to God's power. Before
Creation, God could assure that no universe ever existed. God has this
power now only if he can alter the past. Few think he can. So events
seem to change God's power. DDI's defenders reply that any change here
is purely extrinsic. God has the power he always has. He has lost a
chance to use it, and so we no longer want to *call* his power a
power to prevent a universe. But God is intrinsically as able as ever
to do so.


Swinburne has argued that immutability is incompatible with acting
freely, writing that an "agent is perfectly free at a certain time if
his action results from his own choice at that time and if his choice
is not itself brought about by anything else. Yet a person immutable
in the strong sense would be unable to perform any action at a certain
time other than what he had previously intended to do. His course of
action being fixed by his past choices, he would not be perfectly
free" (1993, p. 222). One thing to note here is that if my past
choices fix my present choice, it does not follow that they bring it
about. It may only follow that it is inevitable that I myself bring
that choice about at that time. So it is not at all clear that
immutability is incompatible even with Swinburnean perfect freedom.
More importantly, Swinburne's "perfect freedom" is a particularly
demanding notion. Even if my own past choices do bring about my
present choice, many libertarians would allow that my present choice
is derivatively free and responsible if the past choices that brought
it about were libertarian-free (see e.g. Kane 1996, Stump 1996,
Ekstrom 2000). Most theists would be quite content with a God with
full libertarian freedom.




A final objection goes thus: God does change extrinsically. Even
full DDI grants this. But whatever changes extrinsically is in time.
For different things are true of it at different times, even if the
'real' changes due to which this is so are in other things.
And whatever is in time changes intrinsically -- it grows older. So DDI
is false. Some would reply by denying that growing older is an
intrinsic change. A more controversial response might be to deny even
extrinsic change to God. This can be done by holding that God is
atemporal. For if God exists at *t* and at a later *t*\*,
and, at *t*, *p* is true of him and, at *t*\*,
*p* is false of him, he does change extrinsically. He bears
different relations to proposition *p*, at least. If God is
atemporal, he exists neither at *t* nor at *t*\* -- his
existence is not temporally located. If this is so, there are never two
times such that different things are true of him at different times.
Rather, all that is ever true of him is true of him timelessly. But a
thing changes, even extrinsically, only if different things are true of
it at different times. Perhaps, then, defending DDI requires commitment
to divine timelessness.