## 1. The Concept of Answered Prayer



What would it mean to say that a petitionary prayer to God had been
answered? Petitionary prayers often make many differences to those who
offer them, whether positive or negative (see Phillips 1981 and
Brummer 2008), but the more philosophically interesting question
is whether or not such prayers make a difference to God. And the
question is not whether God simply hears or notices such
prayers--after all, we have assumed that God knows everything
that happens in the world and is perfectly good. Typically, when
philosophers discuss the effectiveness of petitionary prayer, they
wonder whether petitionary prayers ever move God to act in some way.
What would it mean to say this?



Philosophers usually assume that a prayer is answered if and only if
God brings about the thing requested in part because of the offering
of the prayer, so that had the prayer not been offered, the thing in
question would not have occurred. If you pray to God for rain tomorrow
and it does rain tomorrow, this all by itself is not enough to say
that your prayer for rain was effective--it must also be the case
that God actually brought about the rain at least in part because of
your prayer. If it would have rained anyway, without your prayer for
rain, then it doesn't seem that your prayer for rain was
effective. So an effective prayer would be a prayer that made a
difference by influencing God to act. (For more on this question, see
Flint 1998, chapter 10, Davison 2017, chapter 2, Pruss 2013, Johnson
2020, and Davison 2022, chapter 3.)


## 2. Divine Immutability and Impassibility



As mentioned above, traditional theists believe that God is immutable
(cannot change) and impassible (cannot be affected by anything
external). These ideas are related to one another, but not identical:
if God is immutable, then God is impassible. But just because God is
impassible, it does not follow that God is immutable--God might
be able to change without being affected by any external source. If
God is both immutable and impassible, then it seems that no
petitionary prayers are effective. 



A number of responses are open to traditional theists at this point.
Some theists have argued that there are independent reasons for saying
that God is neither immutable nor impassible. For example, many people
have argued that God is both compassionate and forgiving. But to be
compassionate or forgiving seems to require being responsive to the
actions of others, so perhaps we should not say that God is immutable
or impassible after all (see the entry on
 God and other ultimates).
 



A different response to the puzzle here would involve characterizing
the concepts of divine immutability and impassibility so that they
apply to God in a way that does not rule out the effectiveness of
petitionary prayers. This is an interesting philosophical project in
its own right (see the discussions in Creel 1985 and the entries on
 God and other ultimates
 and
 immutability),
 but its prospects for success fall beyond the scope of this
article.



Finally, a third response would involve claiming that in cases of
apparently effective prayer, God is not really responding to the
prayer but instead bringing about events as part of a providential
plan, a plan that includes both the prayer and the apparent answer to
it. Such a position is suggested by the following remark from St.
Thomas Aquinas: "We pray not in order to change the divine
disposition but for the sake of acquiring by petitionary prayer what
God has disposed to be achieved by prayer (quoted and discussed at
length in Stump 1979)." Given the way that we have characterized
effective prayer above, though, this approach seems to deny that
petitionary prayers are effective, so it would not solve the problem
at hand. 


## 3. Divine Omniscience



A different puzzle concerning the effectiveness of petitionary prayer
arises in connection with divine omniscience, the idea that God knows
everything that can be known. If God already knows the future, for
instance, then how can petitionary prayer make a difference? The
future, after all, is just the set of things that will happen. If God
knows the future in all of its detail, then it seems that there is no
room for petitionary prayers to be effective: either the thing
requested in prayer is something that God already knows will be done,
or it isn't, and either way, it looks like the prayer can make
no difference. Like many other questions in theology, this puzzle
raises an interesting question about the limits of God's
knowledge. Is it possible for anyone, including God, to know the
future in all of its detail? Philosophers disagree sharply about this.
Here we will explore briefly three possible answers to this question.
(For more on this, see Borland 2006 (Other Internet Resources) and the
entries on
 omniscience
 and
 prophecy.)



First, according to the view known as "open theism," God
cannot know those parts of the future that are yet to be determined,
such as the future free actions of human beings, either because there
are no truths to be known yet or because there is no way for anyone,
including God, to know them (see Hasker 1989, Rissler 2006, the entry
on
 process theism,
 Other Internet Resources). This does not mean the God is not
omniscient, because God still knows everything that can be known (and
that is what it means to be omniscient, according to open theists). So
open theists have a way to defuse the puzzle for petitionary prayer
involving omniscience concerning the future: if our prayers are free,
or God's decision whether or not to answer them is free (or
both), then those things cannot be part of a determined future and God
cannot know about them in advance. But open theism is controversial
because (among other things: see Rissler 2006) it appears to deny
something that theists have affirmed traditionally, namely, that God
knows the future in all of its detail.



Second, there is something called the "middle knowledge"
view. This position holds that God knows the future in all of its
detail as a result of knowing both (1) what everyone and everything
would do in any possible situation and (2) which situations everyone
and everything will be placed in actually (see Flint 1998). According
to this picture, God knows the future in all of its detail, but what
God knows about the future free choices of human beings depends on
what they would choose--and that is something that is up to the
human beings in question, not up to God. Even though God knows what
you will do in the future, according to this picture, it is still up
to you. In fact, when you make a free choice, you have the ability to
do something such that were you to do it, God would have always known
something different from what he knows in fact. (This is sometimes
described in terms of having so-called "counterfactual
power" with respect to God's knowledge: see Flint
1998.)



According to the proponents of middle knowledge, then, petitionary
prayer can still make a difference because God can take into account
those prayers that can be offered in the future when God plans how to
create the world over time. The mere fact that God knows the future in
all of its detail does not mean that this future is determined. So the
proponents of middle knowledge have a way to answer the puzzle
concerning omniscience. But the theory of middle knowledge is very
controversial; critics wonder whether there are truths about what
everyone and everything would do in every situation, and even if there
were, how God could know such things (see the entry on
 prophecy and Zagzebski 2011).



Defenders of a view called "timeless eternity" hold that
God knows all of history at once, from a point of view outside of time
altogether (see the entry on
 eternity.)
 Like the proponents of middle knowledge, the defenders of timeless
eternity will say that just because God knows the future, this does
not mean that God determines it. They will also say that God's
single act of creation from outside of time has many effects in time,
including, perhaps, answers to prayers that God anticipates from the
point of view of eternity. In this way, the defenders of timeless
eternity can answer the puzzle concerning omniscience. But like open
theism and the theory of middle knowledge, the idea that God is
timelessly eternal is controversial too; for one thing, if God can
tell from the point of view of eternity what people will pray in the
future, God should also be able to tell what God will do (if anything)
in that same future, so it is hard to see how such knowledge could
inform divine choices (see Hasker 1989, Flint 1998, Pruss 2007, Hunt
2009, and Zagzebski 2011).



It is worth noting, in this section, the view known as "theological
determinism," according to which God determines everything in every
detail, and so knows the past, present, and future on this basis.
Although theological determinism raises other questions about
creaturely responsibility and the problem of evil, it certainly
explains how God could know about future prayers in a way that permits
God to answer them. (For more on these questions, see Hasker 1989,
Timpe and Speak 2016, White 2019, and Furlong 2019.)



It is also worth noting, in this section, that some philosophers have
argued that not only does it make sense to pray for the future if God
exists, but also it makes sense to pray for the past as
well--such prayers could be effective, depending on the extent of
God's knowledge. For example, given the way we have described
effective petitionary prayer, it could be possible for a prayer for
something to have happened yesterday to be effective, as long as the
thing in question actually did happen yesterday. This is because God
could know that I would offer the prayer in the future, and could have
taken this into account yesterday, as long as God can know the future.
So defenders of middle knowledge and timeless eternity can say that
prayers for the past might be effective (but open theists, it seems,
cannot say this: for more on this question, see Timpe 2005).


## 4. Divine Moral Perfection



Theists have traditionally recognized a number of limits on
God's actions. For instance, it is common to insist that
God's omnipotence does not imply that God can do impossible
things, such as create stones that are too heavy for God to lift. It
is also common to insist that God cannot do that which is
intrinsically evil, because God is morally perfect. (For a discussion
of petitionary prayers for bad things, see Smilansky 2012.) Since God
is provident, one might also suspect that God would not answer
petitionary prayers for things that would interfere with God's
providential plans for the world. Within these limits, one might
wonder whether there is enough room among the space of God's
reasons for petitionary prayers to make a difference, and what kinds
of reasons such prayers could provide for God.



Some have argued that God's moral perfection implies that
petitionary prayers cannot make a difference because God will do what
is best for everyone whether or not anyone ever offers petitionary
prayers for those things. If this were so, then it would seem that
petitionary prayers are never answered in the sense described
above.



In response to this worry, a number of authors have suggested that it
would be better, in some cases, for God to bring certain things about
in response to petitionary prayers than to bring about those same
things independently of any such requests. In order to explore this
idea, it is helpful to draw a distinction. Sometimes people pray for
themselves, and sometimes they pray for others. Let's call the
first kind of prayer "self-directed," and let's call
the second kind of prayer "other-directed."



First, consider self-directed prayers. Eleonore Stump argues that in
some cases, God waits for us to ask for something before granting it
in order to avoid spoiling or overwhelming us. We could be spoiled by
God if God answered all of our prayers automatically, and we could be
overwhelmed by God if God provided everything good for us without
waiting for us to ask first (Stump 1979). In a similar vein, Michael
Murray and Kurt Meyers argue that by making the provision of certain
things dependent on petitionary prayer, God helps us to avoid
idolatry, which is a sense of complete self-sufficiency that fails to
recognize God as the source of all good things. They also say that
requiring petitionary prayer in some cases helps us to learn about
God's will as we recognize the patterns in prayers answered (and
not answered: see Murray and Meyers 1994 and section 5 below).



Second, consider other-directed prayers. Murray and Meyers argue that
if God makes the provision of certain things for others dependent on
our prayers for them, then this can help to build interdependence and
community (Murray and Meyers 1994). By contrast, Richard Swinburne and
Daniel and Frances Howard-Snyder argue that by requiring petitionary
prayers in some cases, God gives us more responsibility for the
well-being of ourselves and others than we would enjoy otherwise
(Swinburne 1998, Howard-Snyder and Howard-Snyder 2011). Critics of
this approach have wondered whether this involves God using others as
a means to an end (Basinger 1983) or whether this really extends our
responsibility for others (Davison 2017, chapter 7).



Finally, some philosophers (for example, Basinger 2004) note that
there are a number of ways to understand God's obligations
toward created persons, only some of which suggest that God's
goodness would be compromised if God withheld things because
petitionary prayers were not offered. So there are a number of
responses that theists can make to the puzzle of petitionary prayer
that stems from divine moral perfection. (For more on this question,
see Davison 2017, chapter 6, and Davison 2022, chapter 4.)


## 5. Epistemology



Would it ever be possible to know or reasonably believe that God has
answered a particular petitionary prayer? As one might expect,
philosophers disagree about this question. Some theists think that for
all we know, for any particular event that happens, God may have had
independent reasons for bringing that event about, so we cannot know
whether or not God brought it about because of a prayer (as opposed to
bringing it about for other reasons--for more on this argument,
see Basinger 2004, Davison 2017, chapter 4, Choi 2016, and Davison
2022, chapter 4). This line of thought is especially interesting in
light of the recent popularity of so-called skeptical theism, which
responds to the problem of evil by claiming that we can never know
exactly how particular events are connected with each other and with
good or bad consequences, some of which may be beyond our
understanding (see McBrayer 2010, Other Internet Resources). Others
argue that as long as people are justified in believing, in general
terms, that God sometimes answers prayers, then it is possible to
believe reasonably that one's petitionary prayer has been
answered when one knows that the thing requested has come to pass (see
Murray and Meyers 1994, Murray 2004, and Choi 2016).



A number of people have tried to conduct statistical studies to
determine whether or not petitionary prayer is effective. These
studies try to measure the differences between groups of people, one
of which is the subject of petitionary prayers, and the other of which
is not. Although some earlier studies suggested a positive correlation
between patient recovery and petitionary prayer (see Byrd 1998;
Harris, *et al*. 1999; and Leibovici 2001), more recent studies
have suggested that the offering of petitionary prayer (and the
knowledge that such prayers were offered) is not positively correlated
with patient recovery (see Benson *et al*. 2006).



Some have suggested, though, that these kinds of studies are flawed
from the outset (see Brummer 2008 and Davison 2017, chapter 5).
It would be difficult to to ensure that some group of people is the
subject of no petitionary prayers, for instance, since it is
impossible to prevent people from praying for those whom they know.
Also, God is typically assumed to be a free person, not a natural
force that acts automatically in all similar cases, so we cannot
assume that God will simply ignore those people for whom petitionary
prayers have not been offered. This means that even if a study showed
some statistically significant difference between the two groups of
people, we could not be sure that it was due to the offering of
petitionary prayers alone, as opposed to some other factor or factors.