Introduction
Suppose
there is just one theory – from evolutionary psychology, for example – that is
inconsistent with Christian belief, and suppose just a few scientists accept or
belief or propose it: does that by itself constitute a science/religion
conflict? How widely accepted must such a theory be, in order to constitute a
science/religion conflict?[1]
Simonian science
– scientific theories incompatible with Christian belief.[2]
Plantinga: [W]hat
should [a Christian with both religious and scientific commitments] think about
scientific theories incompatible with Christian belief? Should the existence of
these theories induce intellectual disquiet, cognitive dissonance? To put the
matter less metaphorically, does the existence of such theories give you a defeater for those beliefs with which
they are incompatible?[3]
I. Defeaters and Their Nature
Rebutting defeaters
– cases in which I learn that the defeated belief is false.[4]
Example – I observe what
appear to be sheep in a field, but am later informed by the owner of the field
that there are no sheep there, but only dogs that resemble sheep.
Undercutting
defeaters – Cases in which I don’t learn that the defeated belief is false,
but instead lose my reason for holding the belief.[5]
Example – I observe what I
believe to be Paul leaving his house, but later learn that Paul has an
identical twin brother currently staying with him, such that I must remain
agnostic about whether the person I’m observing is really Paul or his twin.
Plantinga: Whether
a belief B is a defeater for another belief B* depends on what else I believe.[6]
Example – I observe what
appear to be sheep in a field, but am later informed by the owner of the field
that there are no sheep there, but only dogs that resemble sheep. However, I
also believe that the owner of the field is a contrarian and loves to
contradict people just for the fun of it (or that the dogs are sheep in
disguise).
Warrant – the
quality that distinguishes knowledge from mere true belief. Warrant, for
Plantinga, consists in a belief being produced by cognitive faculties
that are functioning properly in an appropriate environment, i.e., according to
their (truth-aimed) design plan.[7]
Warrant defeaters –
Circumstances that result in my belief’s failing to have warrant in a state of
affairs where it would otherwise have it.[8]
Example – observing what I
believe to be a barn in a field, but learning that natives have erected 4 times
as many barn facades as there were real barns, such that, even with my
faculties working reliably, it could only be by sheer luck that I form the
belief with respect to a real barn.
Rationality defeaters
– A belief or experience that undermines the warrant of another belief, e.g.,
the belief that our epistemic faculties are not truth-aimed.
Example – [A]lthough a naturalist will continue to assume R[, i.e., the
proposition that our faculties are "reliable", where, roughly, a
cognitive faculty is "reliable" if the great bulk of its deliverances
are true,] "but (if he reflects on the matter) he will also think, sadly
enough, that what he can't help believing is unlikely to be true."[9]
All
rationality defeaters are warrant defeaters; the converse, of course, doesn’t
hold. A rationality defeater, furthermore, will be a belief (or an experience);
a warrant defeater need not be, but will ordinarily be just some feature of the
environment, as in the barn case above. One need not be aware of warrant
defeaters, and in the typical case of warrant defeaters that are not also
rationality defeaters, one is not aware of them; a rationality defeater,
however, is ordinarily a belief of which one is in fact aware. Finally, if you
come to know about a situation that constitutes a warrant defeater for a belief
you hold, then (typically) you also have a rationality defeater for that
belief.[10]
Q1: What is the
difference between a warrant defeater and a rationality defeater? Does anyone
have any objections to Plantinga’s definitions above?
II. Evidence Base
Evidence base –
the set of beliefs I use, or to which I appeal, in conducting an inquiry…One of
the main functions of one’s evidence base, therefore, is that of evaluating
possible hypotheses, evaluating them as plausible and probable of implausible
and improbable…It is the evidence base that determines the initial plausibility
or probability of a proposed scientific theory.[11]
[T]he
evidence base of a Christian theist will include theism, belief in God and also
the main lines of the Christian faith; therefore it will assign a high
probability to hypotheses probable with respect to the Christian faith.[12]…The
evidence base of a scientific inquiry will not contain propositions obviously
entailing the existence of God (or other supernatural beings); nor will it
include propositions one knows or thinks one knows by way of revelation.[13]…[Therefore,]
the scientific evidence base is importantly different from a Christian evidence
base.[14]
Q2: Should
beliefs in themselves constitute evidence? Shouldn’t a belief also have some
degree of independent warrant itself to be considered evidence?
à
Plantinga: Perhaps this is the case with respect to certain beliefs, but
not “properly basic beliefs.”
Q3: If what
justifies religious belief is its status as a properly basic belief – which
Plantinga admits encompasses only crude religious propositions (like God’s
existence, for example)[15] –
then how is it that all the finer-grained details of the Christian faith (e.g.,
the virgin birth, the divinity of Jesus, etc.) also get included, such that
merely believing those propositions justifies someone in treating them as
evidence?[16]
Plantinga seems to be offering a sort of Bayesian probability
analysis to the question of whether particular beliefs are warranted.
Specifically, he seems to be treating one’s background beliefs as the
assumption upon which subsequent probabilities are assessed, such that a belief
is warranted just in case it has a high probability of being true given that
one’s background beliefs are true.
Q4: Why think
that the probability of a state of affairs given that one’s background beliefs
are true makes a person warranted in believing that state of affairs? Do you
think a Bayesian analysis is appropriate in this context?
III. Methodological Naturalism
Methodological
Naturalism (MN) – A proposed
condition or constraint on proper science, or the proper practice of science,
not a statement about the nature of the universe [i.e., not ontological
naturalism]…More generally, the idea is that in science we should proceed as if
the supernatural is not given: in science, we can’t properly appeal to God’s
creative activity, but we also can’t appeal to angels and demons.[17]
(1) For
any scientific theory, there is its data set or data model; roughly speaking we
can think of the data or phenomena that are to be explained by the theory in
question…The data must be presented or stated in terms of certain parameters or
categories; it could include, for example, the results of certain experiments,
but will not (ordinarily) include alleged information described as hearsay. According
to the MN, furthermore, the data model of a proper scientific theory will not
invoke God or other supernatural agents, or employ what one knows or thinks one
knows by way of revelation.[18]
(2) [A]ccording
to MN the parameters for a scientific theory are not to include reference to
God or any other supernatural agents (although, again, they can refer to
beliefs about the supernatural); and the theory, like the data set, also can’t
employ what one knows or thinks one knows by way of revelation.[19]
(3) MN
also imposes a constraint on the evidence base of any scientific inquiry. This
evidence base will include mathematics and logic, relevant current science,
various common sense beliefs and propositions (for example, that there is an
external world, and that the world has existed for a long time), and perhaps
also maxims outlining proper scientific procedure.[20]
Eugenie Scott –
“Science neither denies or opposes the supernatural, but ignores the
supernatural for methodological reasons.”[21]
Q5: Do you think
that MN is appropriate to the context of scientific investigation and
theorizing? Why or why not?
Plantinga: Simonian
science…incorporates the denials of crucial elements of the Christian faith in
its evidence base.[22]
Weak MN – According
to weak MN, a scientific evidence base will not include the proposition that
there is such a person as God, or any other supernatural being; nor, of course,
will it include the main lines of the Christian faith.[23]
Strong MN – Strong
MN goes further; it adds the denials of at least some of these beliefs to the
evidence base.[24]
IV. Is Simonian Science a Defeater for Christian Belief?
Plantinga: [T]hat
conclusion is a simple consequence of the evidence they start with (MN). Their
coming to that conclusion from the starting point is surely no reason to give
up or moderate belief in the resurrection of Jesus; it does not constitute a
defeater for that belief.[25]
Q6: Does science,
in some sense, beg the question against theism through its methodological
commitments?
For Plantinga’s argument here to succeed, we would have to
assume that scientists were committed to Strong MN, i.e., assume that scientists
employed MN as a sort of premise from which they deduced their conclusions.
Q7: Is this the
right way to think of the role of MN in scientific investigation? Is it really
an assumption from which inferences are drawn (Strong MN), or is it rather the
necessary consequence of not taking God’s existence for granted, i.e., the
resistance to “positing entities beyond necessity” (Weak MN)? Is it right to
think of MN as a positive metaphysical claim at all (Strong MN), or does it
merely represent the terminus of what we can fairly conclude given the evidence
that we have (Weak MN)?
[W]hat
the success of Simonian science really shows is something like this: that with
respect to its evidence base, its conclusions are probable, or sensible, or
approvable as science or as good science. What is shows with respect to the
Christian’s evidence base, therefore, is that from the perspective of part of that evidence base – the part
coinciding with the scientific evidence base – the Simonian conclusions are
probable, or sensible, or approvable, or constitute good science. Therefore
what it shows is that with respect to part
of [the Christian theist’s] evidence base, some of her beliefs are improbable
or unlikely. That need not give her a defeater for those beliefs. For it can
easily happen that I come to see that one of my beliefs in unlikely with
respect to part of my evidence base, without thereby incurring a defeater for
that belief.[26]
The suggestion is that the Christian theist possesses other
“evidence” (the unmentioned parts of her evidence base) that mitigates the
doubt-raising evidence of EP and HBC. In fact, the claim is stronger than that;
it is that science, on MN, provides an incomplete evidence base and, therefore,
yields incomplete conclusions. The implication seems to be that science plus
theism would provide a complete evidence base that would yield more complete
conclusions.[27] This is
the consummation of an argument that Plantinga has been employing in a more
narrow capacity now for 5 chapters.
For
the Christian, Simonian science is like truncated physics. Concede that from
the point of view of the evidence base of Simonian science, constrained as it
is by MN, Simonian science is indeed the way to go (and of course perhaps it
isn’t): this need not give the Christian a defeater for those of her beliefs
contradicted by Simonian science; for the evidence base of the latter is only
part of her evidence base.[28]
Q8: Do you think
there could be a successful scientific enterprise that doesn’t include MN, or
even includes methodological theism (MT) or methodological Christianity (MC)?
Why or why not? If so, what would that science look like?[29]
Plantinga: Does
the jury’s decision give me a defeater for my belief that I’m innocent?
à No…And the reason is that I have a source of
knowledge or warranted belief they don’t: I remember that I didn’t commit that
crime?
Q9: What is the
Christian supposed to have in his/her evidence base that corresponds to
Plantinga’s memory that he didn’t slash the tires on my car? Are you
comfortable with his equivalent use of knowledge and warranted belief, where
warranted belief simply means properly basic belief (i.e., belief for which we
need no independent evidence to support our confidence in)?
V. Faith and Reason
Problem of Faith and
Reason –
According
to classical Christian belief, there are two sources of knowledge or rational
opinion: faith and reason. Reason includes such faculties as perception, a
priori intuition (whereby one knows truths of mathematics and truths of logic),
memory, testimony (whereby one can learn from others), induction (whereby one
can learn from experience) and perhaps others, such as Thomas Reid’s sympathy,
whereby we know of the thoughts and feelings of other people. Perhaps there is
also a moral sense, whereby we know something of what is right and wrong;
perhaps there are still others. These faculties or sources of belief/knowledge
are part of our created cognitive nature; every properly functioning human
being has them…Faith on the other hand, is a wholly different kettle of fish:
according to the Christian tradition (including both Thomas Aquinas and John
Calvin), faith is a special gift from God, not part of our ordinary epistemic
equipment. Faith is a source of belief, a source that goes beyond the faculties
included in reason.[30]
Q10: Is this the
proper way to think of faith? Is biblical faith really akin to the epistemic
faculties, i.e., a source of beliefs/knowledge?
Plantinga: [T]he
mere fact that the deliverances of faith include propositions not among the
deliverances of reason doesn’t show that there is…a conflict between faith and
reason.[31]
Weak conflict –
[M]y acquiring the evidence for having committed the crime (the same evidence
as the jurors have for that proposition) doesn’t give me a defeater for my
belief, based on memory, that in fact I didn’t commit the crime. It doesn’t
give me a reason to give up that belief, or even to hold it less firmly.[32]
Plantinga: How much evidence of that sort would be
required to give me a defeater?
à How much would depend on the reliability of the
witnesses, the question what I know or believe about whether my memory had ever
before failed me in such drastic fashion, and so on.[33]
Strong conflict –
[O]nly…sufficient evidence of that sort could give me a defeater for my belief
that I was innocent, and where that does in fact happen, what we have is a
strong conflict between memory and these other sources of belief.[34]
Plantinga: My
evidence base contains the belief that God has created human beings in his
image. I now learn that, given an evidence base that doesn’t contain that belief, the right thing to believe is that
those mechanisms are not truth-aimed; but of course that doesn’t give me any
reason at all to amend or reject my belief that in fact they are truth aimed.[35]
Q11: Rather than
treat a person’s background beliefs as evidence
for a claim, isn’t it more reasonable to treat them as alternative hypotheses, and then test those hypotheses against experience
to see which is the true one, especially in cases like this in which the two
alternative hypotheses make different predictions? Should we treat different
background beliefs in our evidence base by different standards, e.g., should
beliefs based on memory be treated distinctly from beliefs based on faith?[36]
Q12: Do you think
evolutionary psychology and biblical criticism represent instances of weak
conflict, strong conflict, or neither?
VI. Can Religious Belief be Defeated?
The
believer could always just say that his evidence base includes the challenged
belief, and is therefore probable with respect to that evidence base (because
entailed by it). But the fact is defeat is not impossible; it sometimes happens
that I do acquire a defeater for a
belief B I hold by learning that B is improbable on some proper subset of my
evidence base.[37]
[I]n
some cases one can indeed acquire a defeater for a belief held on the basis of
the Bible; I can come to see that what the Bible teaches isn’t what I thought
it was.[38]
Q13: Can
religious beliefs only be defeated by facts internal
to that way of thinking, i.e., other religious beliefs, like what the Bible “really” teaches? If so, wouldn’t that
effectively exclude certain conclusions from ever being drawn by the theist, namely
a conclusion that contradicts some essential tenet of his/her faith, like that
the Bible is not inspired, or that God doesn’t exist?
Types of defeaters for religious belief:
(2) …
Plantinga: How is
it that you get a defeater in some case of this sort, but not in others? What
makes the difference?
à [T]he one case conforms to the definition of
rationality defeat, and the other one doesn’t.
Plantinga: I am
prepared to believe whatever the Lord teaches; what he teaches is
non-negotiable. But it isn’t always easy to determine just what he does teach in a given passage; might it
not be, with respect to this passage, that the message endorsed by God is not
(N) but something else? What is my reason for thinking that (N) is indeed what
the Lord is teaching in this passage?[40]
Q14: How might
Plantinga respond to the challenge that it is not always easy either to
determine if God has in fact taught anything at all, and that this consideration
imposes at least some pressure on the theist to consider not only alternative
interpretations of biblical passages when confronted with facts that seem to
contradict it, but also the rejection of biblical passages as well?
VII. The Reductionist Test
The reduction test
for defeat –
The
right question, perhaps, is this: is (B) epistemically improbable or unlikely
with respect to that new evidence base? If it is, perhaps we have a defeater;
is not, not…The idea – call it “the reduction test for defeat” – is that (A) is
a defeater for (B) just if (B) is relatively improbable – epistemically
improbable – with respect to EBme-(B)..., where EBme-(B)
is any subset of EBme that doesn’t entail (B) and is otherwise
maximally similar to EBme.[41]
(This
reduction condition is Plantinga’s means of avoiding the charge of begging the
question.)
Perhaps
[the reduction test for defeat] states a necessary condition of rationality
defeat: perhaps, whenever I get a defeater for a belief (B) by way of acquiring
a new belief (A), B will be relatively improbable with respect to EBme-(B).
But this condition is nowhere nearly sufficient for defeat…For it might be,
clearly enough, that (B) has a lot of warrant on its own, intrinsic warrant,
warrant it doesn’t get from the other members of EBme or indeed any
other propositions; (B) may be basic with respect to its warrant. But then the
fact that it is unlikely with respect to EBme-(B) doesn’t show for a
moment that the belief isn’t perfectly rational.[42]
In
a case like this, whether I have a defeater for the belief P in question will
depend, on the one hand, upon the strength of the intrinsic warrant enjoyed by
P, and, on the other, the strength of the evidence against P from EBme-P.[43]
Q15: What do you
think about Plantinga’s reduction test for defeat? Do you think it successfully
defends theism from the “superficial conflicts” presented by evolutionary psychology
and biblical criticism? Why or why not?
Plantinga: The
Christian can think of Simonian science as specifying how things look from a
given perspective, how they look given a particular evidence base, an evidence
base that includes only a part of the Christian evidence base. The mere
existence of Simonian science – science that comes to conclusions incompatible
with tenets of the Christian faith – has no tendency to produce a defeater for
those tenets…Simonian science specifies how things look from a given
perspective or evidence base, a perspective characterized by methodological naturalism.[44]
Q16: Are you
satisfied with Plantinga’s defense against the claim that evolutionary
psychology and biblical criticism provide defeaters for Christian belief? Why
or why not?
[1] P. 167.
[2] P. 168.
[3] P. 168.
[4] p. 169.
[5] p. 169.
[6] P. 169.
[7] Note that
Plantinga’s account seems to allow for someone to have knowledge even in the
case in which his/her belief is not true, since warrant only requires that the
faculties that produce it produce true beliefs most of the time, i.e., produce
beliefs with a high probability of being true.
[8] P. 170-171.
[9] Wikipedia. “Evolutionary argument against naturalism.” http://en.wikipedia.org/wiki/Evolutionary_argument_against_naturalism.
Quote is cited from Beilby(2002) p.
211.
[10] P. 170-171.
[11] P. 171-172, 177.
[12] P. 172.
[13] P. 177.
[14] P. 177.
[15] See p. 62-63.
[16] Plantinga recognizes these beliefs as constituting
evidence on p. 172 and 177.
[17] P. 174.
[18] P. 176.
[19] P. 176.
[20] P. 177.
[21] P. 174.
[22] p. 178.
[23] p. 178.
[24] P. 178.
[25] P. 179.
[26] P. 180.
[27] See p. 180.
[28] P. 182.
[29] Plantinga suggests this more explicitly on p. 195.
[30] P. 182-183.
[31] P. 183.
[32] P. 184.
[33] P. 184-185.
[34] P. 185.
[35] P. 185.
[36] The reason I raise this last question is because
Plantinga’s example in which he remembers not slashing the tires has some
initial plausibility to it, while the principle he seeks to draw from this
example, i.e., that all background
beliefs serve equally as evidence, including faith in tenets taught in
scripture, doesn’t seem nearly as plausible. Why doesn’t the plausibility of
the example extend also to the faith case?
[37] P. 188.
[38] P. 190.
[39] P. 188.
[40] P. 189.
[41] P. 191-192.
[42] P. 193.
[43] P. 194.
[44] P. 195.
