Transcript Truth as the aim of epistemic justification

Truth as the aim of
epistemic justification
Asbjørn Steglich-Petersen
Department of Philosophy
University of Aarhus
1
‘Believing aims at truth’
 Many philosophers have been attracted to the idea that beliefs ‘aim’
at truth.
 Some understand this in normative terms, as expressing a
fundamental norm of correctness for belief, e.g. that believing P is
correct (if and) only if P is true.
 Others (me included) understand it in teleological terms, as the claim
that when a person believes that P, she has the aim of believing P truly
(or has some sub-intentional surrogate of such an aim).
 The teleological account entails a criterion of success: believing P is
successful (with respect to the truth-aim) if and only if P is true.
 However: the problem I wish to discuss is relevant for both
normativists and teleologists about the truth aim.
2
Truth and guidance
 Most defenders of the truth aim recognize that truth cannot be
the only relevant consideration when evaluating belief.
 The problem is that the truth of a proposition, in itself, offers
little guidance for someone wishing to form a belief about it.
 It seems that the mere truth of a proposition doesn’t make it
the case that I ought to believe it, nor does its falsity make it the
case that I ought to disbelieve it.
 The additional relevant consideration is often expressed in
terms of epistemic justification, or a requirement that beliefs are
adequately backed by epistemic reasons.
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The truth aim and justification
 The mere fact that truth cannot be the only relevant
consideration raises several issues:
 If truth doesn’t determine when a belief is justified, what
does?
 If beliefs can be evaluated both in terms of truth and
justification, what is the relation between those kinds of
evaluation? It would be odd if they are completely distinct.
 If epistemic justification determines what a person ought
to believe in any given situation, is there any reason to
hold on to evaluation in terms of truth? Is the truth aim
then obsolete?
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A simple account
 Many have been attracted to a simple account of the
relationship between justification and the truth-aim, which
answers all of the above worries:
 The point of the requirement that we only believe what we are
justified in believing is to advance the ultimate aim of believing
the truth about the relevant propositions. We seek justification
for our beliefs in order to believe the truth.
 Apart from being strikingly simple, this account has what many
regard as the virtue of assimilating the normativity of epistemic
justification to instrumental normativity, which many find
relatively unproblematic. This is so especially in the context of a
teleological understanding of the truth aim.
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A problem
 As a number of philosophers have pointed out, however,
there is a basic problem with the simple account: it is
forced to denying the possibility of justified false beliefs.
 There are a number of arguments for this claim floating in
the literature. I shall focus on Stephen Maitzen (1995) and
Richard Fumerton (2001; 2002).
 A similar argument (citing Fumerton 2001) has recently
been invoked by Kathrin Glüer and Åsa Wikforss (2009: 4445), as a part of an attack on the idea of beliefs aiming at
truth.
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Maitzen’s argument
 Maitzen starts with a simple argument:
 Suppose for reductio that the point of justification is to
advance the aim of believing only truths.
 It follows that beliefs are justified if they advance that aim,
and unjustified if they don’t.
 But only true beliefs will advance the truth aim.
 So beliefs are justified only if they are true, which,
according to Maitzen is an absurdity. So, the point of
justification cannot be to advance the aim of believing
only truths
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Maitzen’s argument
 The obvious response to this simple argument is that the justification
of a belief doesn’t depend on whether the belief itself furthers the
truth aim, but whether the methods by which it was formed tends to
further the truth aim.
 But according to Maitzen, this response results in a dilemma: either
the justifying methods will be inconsistent with the ultimate aim of
truth, or they will disallow justified true beliefs.
 The dilemma is a version of the well-known dilemma for ruleutilitarianism: either the rules will be inconsistent with the basic aim of
maximizing utility, or the rules will effectively recommend the same
as, and thus collapse into act-utilitarianism.
 There is a further similarity between these two dilemmas: many have
been attracted to rule-utilitarianism because it seems to provide
guidance, as opposed to the act-based version. Analogously, the
justification norm is needed because the truth norm cannot guide.
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Fumerton’s argument
 Fumerton’s argument is even simpler:
 Suppose for reductio that justification gets its point from advancing
the aim of believing what is true with respect to some specific
proposition P.
 The only way of advancing the aim of believing what is true with
respect to P is to believe P when P is true.
 So if the point of justification is to advance that aim, whatever the
exact content of the justification norm might be, it cannot allow
justified false beliefs.
 But that is absurd, so the supposition fails.
 Further, identifying justification what what one is justified in believing
will advance the aim of believing what is true with respect to some
proposition would be circular.
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In a nutshell
 If the aim of justifying one’s beliefs is to end up believing
the truth, success in justifying a belief must entail that the
belief is true.
 But it is possible for a false belief to be justified; it is
possible for a belief to be successfully justified but not
true.
 So the aim of justifying one’s beliefs cannot be that of
ending up believing the truth.
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My strategy
 In the following I shall defend the simple account of justification
as an instrument to believing the truth, by arguing that we can
reject a crucial premise: that there cannot be justified false
beliefs (at least in the relevant sense of ‘justification’).
 I first define the sense of ‘justification’ that is relevant to our
purposes.
 The then consider three popular intuitions in favor of the
possibility of justified false beliefs, and find them wanting.
 Finally, I sketch an alternative account of justification that does
not allow justified false beliefs, and show how the account is
less unpalatable that commonly supposed.
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‘Justification’
 The sense of ‘justification’ relevant to our purposes, is the sense which
addresses the problem that truth by itself doesn’t provide guidance. This
can be understood in terms of reasons.
 In asking whether some fact could justify S in believing P, I shall focus on
whether that fact could act as an adequate epistemic reason for which S
believes that P.
 A type of fact justifies S in believing P, in this sense, if mentioning that a
fact of that type obtains would be an adequate, i.e. sufficient, answer on
S’s behalf to the question ‘what gives you epistemic reason to believe that
P?’
 Call this the ‘reasons constraint’ on the relevant sense of justification.
 Although this may seem like not much of a constraint, some notions of
justification fails to satisfy it.
 With this in mind, we can go on to consider the three popular intuitions.
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Probabilism
 The first popular intuition in favor of the possibility of justified false beliefs
is what I call ‘Probabilism’:
Probabilism: when the evidential probability for S that P is sufficiently
high, but not necessarily 1, S has justification for believing that P.
•
The thesis does not amount to a definition of justification, but is a mere
sufficiency claim. We needn’t consider an analogous necessity claim.
•
The thesis concerns propositional justification rather than doxastic
justification.
•
The thesis is silent on the access S must have to the antecedent condition
in order for it to justify the belief. I shall leave this issue for now, but in the
meantime note that it makes sense to ask: ‘Suppose that R is the case, and
S has adequate access to R, would R then be an adequate reason for S to
ϕ?’. My criticism of Probabilism grants the relevant access, and concerns
this latter question only.
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Probabilism
 Probabilism allows justified false beliefs, since it is possible for a
proposition to have an arbitrarily high evidential probability
short of 1, and yet be false.
 Lotteries provide an especially vivid example where this is the
case: it has seemed plausible to many that if S holds a single
ticket in a large fair lottery, and knows this, S has justification
for believing that she will loose, despite the slight but real
possibility that she won’t.
 My argument against probabilism has two components: I first
argue that probabilism is committed to allowing an irrational or
even paradoxical practice of belief formation (what I call
‘doxastic risk’), and later argue that the appeal of probabilism
can be accounted for in other ways.
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Doxastic risk
 An action is taken under risk whenever the agent has mere
probabilistic knowledge of the states of nature relevant to
the success of the action (standard decision theoretic
definition).
 The states of nature relevant to the success of forming a
belief, are the states in nature in which the proposition
believed is true and false, respectively.
 This yields the following definition of doxastic risk:
Doxastic risk: when S forms a belief that P while having
mere probabilistic knowledge that doing so will result in
believing P truly, S forms the belief under risk.
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Doxastic risk is paradoxical
 When action is performed under risk, or at least perceived risk,
the agent performs the action in the hope that a particular
outcome will ensue. She doesn’t believe that it will ensue, since
if she did, she wouldn’t regard the action as risky.
 This means that there is something paradoxical about the
notion of doxastic risk, since in this case, the risky ‘action’ is
exactly a belief that the success condition for the action will
ensue, which contradicts the idea that it was performed under
risk.
 One cannot consistently regard oneself as taking a risk in some
particular act if one knows that taking the act will entail not
regarding the action as risky.
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Doxastic risk is paradoxical
 Might this paradoxical situation be resolved by observing that ‘under
risk’ refers to the agent’s doxastic situation prior to completing the
act?
 For example, bringing an umbrella on a walk might be risky in the
sense that I, prior to and during portions of the walk, am unsure that it
will rain. This risk is compatible with me coming to believe that it rains,
if it indeed starts to rain.
 Analogously, perhaps all it takes for a belief that P to be risky, is that it
was formed while the agent was unsure whether P. This is compatible
with no longer being unsure whether P once the belief that P is
formed.
 But in contrast to the umbrella-case, such a change in doxastic state
would either be unfounded, founded upon the very doxastic state it is
a revision of, or founded on new evidence. But neither of these
options are very attractive for the Probabilist.
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Doxastic risk is irrational
 It seems, in fact, that forming a belief under doxastic risk will always
result in rationally incompatible beliefs:
 Suppose that S finds that the probability of P upon her evidence is .6
(call this her ‘evidential belief’), and suppose for the sake of argument
that .6 is the Probabilist threshold of evidential probability for justified
belief.
 Since one can form a belief in response to an evidential belief only if
one doesn’t thereby revise the evidential belief, Probabilism then
recommends that S both believes that evidential probability that P is
.6 and believes that P. These seem like rationally incompatible beliefs.
 The obvious response is to raise the threshold to some value higher
than .6, but short of 1. But there does not seem to be any value short
of one, which would make the evidential belief and the outright belief
rationally compatible.
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Doxastic risk is irrational
 It may be objected that since P, and the proposition that
the probability of P upon a person’s evidence is some value
short of 1, can both be true at once, that person can
believe both propositions without contradiction, and thus
without irrationality.
 But the fact that two propositions can be true at once does
not make the pair of those propositions available for
rational belief. Moorean absurdities (‘P and I do not
believe that P’) provide examples of this.
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Doxastic risk is irrational
 Still, some may insist that judging belief in such pairs of
propositions irrational begs the question against Probabilism.
But consider the role of such pairs in rationalizing action:
 Suppose that S has to decide whether to ϕ where the success of
ϕ-ing is P-dependent.
 Suppose that S believes both that P and that the probability of
P upon her total evidence is .9.
 It is not difficult to imagine situations in which she should ϕ in
response to the one belief, but not in response to the other,
thus leaving the agent with conflicting recommendations.
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Doxastic risk is irrational
 It is no help for the Probabilist to claim that the evidential belief
is relevant to the rationality of action only via rationalizing an
outright belief, since in the context of an action, the rationality
of which depends on the exact probability that it will be
successful, it should strike us as especially implausible to let an
evidential probability short of 1 justify an outright belief.
 Nor is it a help to point to decision theoretic rules taking
probability intervals or fuzzy probability regions as inputs, since
by hypothesis, no such intervals or fuzzy probabilities exist in
the case at hand.
 So it seems that Probabilism is committed to an irrational
practice of belief formation.
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Credence probabilism
 The obvious Probabilist reply to the above difficulties is to retreat to a
principle concerning the justification of degrees of credence:
Credence probabilism: when the evidential probability for S that P is D, S
has justification for adopting credence in P to degree D.
•
But this doesn’t in itself say anything about the justification of outright
belief. To that end we need a bridge principle connecting justified
credence to justified belief.
•
One such popular principle is the Lockean Thesis:
The Lockean Thesis: Outright belief that P = Any degree of credence
above threshold T.
•
These two principles jointly imply that when the evidential probability for
S that P is above a certain threshold short of 1, S will be justified in an
outright belief that P. But since this belief is ‘really’ just a degree of
credence, it does not count as ‘risky’ in the problematic sense.
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Credence probabilism
 However, the combination of credence probabilism and the Lockean
Thesis gives rise to new problems.
 Consider the following plausible thesis about the justification of assertion:
The belief-assertion principle: when S is epistemically justified in believing
P, S is epistemically justified in asserting P.
•
If this is correct, Credence probabilism and the Lockean Thesis entail that
when the evidential probability for S that P is above a certain threshold
short of 1, S is justified in asserting that P. But that seems false (cf.
Williamson 2000: 246).
•
So either Credence probabilism or the Lockean Thesis have to go, but
giving up either will block Credence probabilism as a response to the
problem of doxastic risk.
•
In sum: Probabilism does not look very promising…
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Reliabilism
 The second main intuition in favor of the possibility of justified false
beliefs, we can call Reliabilism:
Reliabilism: when S has formed her belief that P according to methods
that reliably (but not invariably) result in true beliefs, S is justified in
believing P.
•
Note that for ease of expression, Reliabilism is formulated as a principle
about doxastic rather than propositional justification.
•
Note also that although Reliabilist theories are not usually designed to
satisfy the reasons constraint, but instead define conditions under which a
belief can be justified even in the absence of any explicit reasoning on
behalf of the believer, it seems that something could satisfy those latter
conditions only if they could also satisfy the reasons constraint.
•
Not all Reliabilist theories of justification allow justified false beliefs
(Armstrong 1973 and Williamson 2000 don’t), but most do. The following
discussion concern only those that do.
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Reliabilism
 There are at least two broad ways one might interpret the
notion of reliability involved.
 The most common interpretation is in terms of the relative
frequency with which beliefs formed in accordance with the
relevant methods are true.
 On this interpretation, Reliabilism is just a special case of
Probabilism, since the method justifies believing P in virtue of
the fact that by forming the belief in accordance with the
method, the agent raises the chance of ending up with a true
belief to a certain level (short of 1).
 My response to this kind of Reliabilism will thus be the same as
my response to Probabilism.
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Reliabilism

The second possible interpretation understand ‘reliable method’ in terms of what
normally happens when a belief is formed in accordance with it, where ‘normally’
expresses something else than mere likelihood.

When what is normal fails to occur, some explanation of this is required, whereas
this is not necessarily the case when what was likely fails to occur. Hence:
Reliabilism Normal: when S has formed her belief that P according to methods
that are such that, were the belief to be false, this would require an explanation, S
is justified in believing P.
•
Smith (forthcoming) gives a compelling illustration of the difference between
what is normal, and what is likely.
•
However: it seems an odd reason to believe a proposition that it is formed in
accordance with a method that is such that it would require an explanation if the
belief turned out false. But in order to substantiate this claim, I must first consider
the last of the three intuitions in favor of justified false beliefs.
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Blamelessness
 The third main intuition in favor of the possibility of justified
false beliefs, I call Blamelessness:
Blamelessness: when the epistemic situation of S is such that S
couldn’t be blamed for believing P even if P is false, S has
justification for believing P.
• The possibility of justified false beliefs does not follow
immediately from this intuition, but when coupled with the
commonplace observation that we frequently are blameless for
false beliefs, it does.
• Vivid examples include skeptical scenarios, but it is easy to
imagine more everyday cases. For example, one can be mislead
by testimony that one has no reason to distrust.
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Blamelessness

There can be no doubt that we can be blameless for believing a falsehood, but it
should also be clear that Blamelessness doesn’t satisfy the reasons constraint, and
thus fails to pick out conditions under which a belief is justified in the defined
sense.

Prima facie, the fact that one would be blameless for believing P is a not an
adequate reason for S to take up a belief that P. This prima facie judgment can be
backed up in the following way:

Note first that for any norm N, we can distinguish between the conditions under
which an agent conforms to N, and the conditions under which the agent is
blameless for failing to conform to N. There is a real difference: when trying to
conform to a norm, we do not (merely) try to satisfy the conditions for being
blameless if we fail to conform.

Given this distinction, if Blamelessness is a genuine norm that we ought to
conform to when forming beliefs, there must be a set of conditions under which
we are blameless for failing to conform to Blamelessness. But that is absurd: there
is no set of conditions under which we are blameless for failing to be blameless in
forming a belief. So Blamelessness should not guide us when forming beliefs.
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Reliabilism again
 I noted above that it seems an odd reason to believe a
proposition, that it is formed in accordance with a method that
is such that it would require an explanation if the belief turned
out false. We can now locate the source of this oddness.
 Observe first that in order for S to be blameless for believing a
falsehood, there must be an excusing explanation for that belief.
 The fact that the proposition was likely given S’s evidence is not
sufficient for this, since unlikely events may be statistically on a
par with their alternatives.
 On the other hand, it seems that if S formed her belief
according to methods that are such that, were the belief to be
false, this would require an explanation, such an explanation
would also suffice to excuse S from blame.
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Reliabilism again
 This suggests the following bold hypothesis: the antecedent conditions of
Reliabilism Normal and Blamelessness are identical, since the
explanations required for justifying a false belief are the same.
 Since what the norms recommend is also identical, the norms would just
be two ways of expressing the same thought, and any argument against
the one norm would also be an argument against the other. So if
Blamelessness shouldn’t guide belief formation, Reliabilism Normal
shouldn’t either.
 This does not entail that it is uninteresting to ask whether a person was
blameless in her false belief. It is frequently of great importance, for
example when deciding whether a person acted in good faith. There may
even be a sense of ‘justification’ that would be the proper label for this
condition.
 But if what we are interested in is the norm that ought to guide us when
forming beliefs, Blamelessness, and hence Reliabilism Normal, is not it.
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A (too?) radical solution
 The problem for the simple account of justification as
truth aiming, raised by Maitzen and Fumerton,
presupposed that there can be justified false beliefs.
 I have argued that some of the most common intuitions in
favor of this possibility fail, at least when it comes to the
relevant sense of ‘justification’.
 I must now argue than an account of justification on which
justification entails truth is less unpalatable as it has
seemed to many.
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A (too?) radical solution

The principle I must defend is what I call Implication:
Implication: S has justification for believing P (if and) only if the truth of P is
implied by S’s evidence.
•
Read as a biconditional, Implication simply identifies propositional justification for
believing P with P being implied by one’s evidence.
•
But for our purposes, it might suffice to establish the weaker claim that it is
necessary for having propositional justification for believing P, that P is implied by
one’s evidence.
•
If the biconditional is true, Implication certainly satisfies the reasons constraint:
the fact that P is implied by S’s evidence would be adequate as a reason for S to
believe that P (given the proper access – more on this later). But in what follows, I
shall focus on defending the weaker necessity claim against three key objections.
•
If evidence is factual (which I shall assume), both versions entail that a belief can be
justified only if it is true.
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The demandingness objection
• I shall consider three objections to the proposed account.
The first, I call the ‘demandingness objection’:
• Many will have the intuition that there could be less
demanding conditions sufficing as adequate reason to
believe some proposition. Will the present proposal not
have the result that most of the beliefs that we commonly
regard as justified won’t be?
 There are (at least) three mitigating considerations worth
pointing to in response.
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The demandingness objection
 The first mitigating considerations is that in many cases where we
wish to form a belief about P, but P is not implied by our evidence, a
proposition about the evidential probability that P is implied by the
evidence, providing justification for believing that probabilistic
proposition instead.
 This is not always the case. There are cases in which the fact that the
evidential probability for S that P is D will not be implied by S’s total
evidence, since even if E is S’s total evidence, E does not imply that S’s
total evidence includes E or that E includes S’s total evidence (thanks
to Tim Williamson for this point).
 But in cases where the agent has access to those latter facts, the
probabilistic proposition is implied by the evidence.
 So even if we are never justified in believing a falsehood, we often
have justification for believing a proposition to be very likely, which
nevertheless turns out false.
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The demandingness objection
 This suggests the possibility that those who have found it
plausible that we can be justified in believing a falsehood, have
done so because of confusing being justified in believing a
proposition, and being justified in believing that proposition to
be very likely. This would explain the allure of Probabilism.
 This theory is supported by the fact that the psychological
reaction (e.g. surprise) upon discovering that a proposition is
false, is likely to be very similar, given the two kinds of prior
attitude, even if the probabilistic belief is not strictly speaking
falsified by the falsity of the proposition believed to be likely.
 What is more justified beliefs concerning such likelihoods are
sufficient as grounds for rational action. They can play the same
role in decision theory as rational degrees of credence.
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The demandingness objection
 The second mitigating consideration is that in cases where we
lack epistemic justification for believing some proposition, we
may nevertheless be justified in accepting that proposition for
some restricted range of purposes, where this justification will
involve a combination of epistemic and non-epistemic factors
(Cohen 1992).
 There may be cases, for instance, where the computing costs of
relying on probabilistic beliefs in deciding what to do exceeds
the potential benefits of doing so, it which case it is reasonable
to instead rely on acceptances of the truth of some simple nonprobabilistic proposition.
 This suggests the possibility that we may sometimes confuse
what we regard as justification for believing P, with what is
really just justification for accepting P.
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The demandingness objection
 The last mitigating consideration is that Implication says nothing about
the conditions under which one can be held blameless for believing a false
proposition.
 Plausibly, one condition for being blameless is that one made an honest
attempt at forming a justified, and thus true belief. As suggested above,
another condition might be that an explanation would be required to
make sense of how the belief could be false given the evidence available
to the believer.
 No doubt, there are many more complex and important things to be said
about these conditions, and there is no harm done in continuing to use the
term ‘justification’ to speak of them, as long as one keeps in mind that
those conditions cannot act as antecedent conditions in a norm that
guides agents when forming beliefs.
 But the feeling that Implication is too demanding may just come down to
confusing justification in the sense defined with the conditions for being
blameless for one’s beliefs.
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The guidance objection

The second objection I shall consider concerns the ability of the proposed
justification norm to guide belief formation.

The point of supplementing the truth norm with a justification norm was that the
truth of a proposition in itself offers little guidance in whether to believe it. Even if
my toaster is on back in Aarhus, I have no reason to believe that it is.

But since I have assumed evidence to be factual, and it also is a factual question
whether some proposition is implied by one’s evidence, does the proposed norm
of justification really provide more guidance than the simple truth norm?

But on any account of evidence, the propositions acting as evidence, and the
implications of these propositions, are the kinds of truths that we can be assumed
to have some degree of access to. This doesn’t mean, of course, that evaluating
one’s evidence in order to apply the justification norm is cognitively effortless or
trivial. But that doesn’t mean we cannot be guided by the justification norm, or
that we can be guided by it only by relying on some more ‘basic’ norm with yet
more transparent antecedent conditions (cf. Williamson 1998: 102).
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Unjustified true beliefs?
 The final objection stems from the possibility of unjustified true beliefs.
 The initial problem was that if the aim of justification is to end up
believing the truth, there cannot be justified false beliefs (beliefs that are
successful vis-à-vis the aim of justification, but not successful vis-à-vis
truth). I have argued that we can accept that implication.
 But there might be a parallel argument: if the aim of justification is to end
up believing the truth, there cannot be unjustified true beliefs (beliefs that
are successful vis-à-vis truth, but not successful vis-à-vis justification).
 That would be an unacceptable result: clearly one can have true but
unjustified beliefs! (Thanks to Tim Williamson for raising this issue).
 This problem resembles the ‘Swamping Problem’: if the purpose of
justification is to ensure true beliefs, we cannot explain why an unjustified
true belief is less valuable than a justified true belief, since the value we
wanted to promote by justifying the belief already obtains.
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Unjustified true beliefs?

Although I cannot deal with this problem in full here, a first response might be this:
while successfully justifying a belief requires that the belief is true, this is not all it
takes for justifying a belief. Truth is necessary, but not sufficient for justification.

This fact is already part of the offered account: truth is necessary but not sufficient
for a proposition to be implied by one’s evidence. The fact that there can be true
but unjustified beliefs does not threaten that truth is one of several criterions of
success for justification.

But this might spoil what I called ‘the simple account’, according to which the point
of justifying one’s beliefs is to end up believing the truth. It may entail that there
are several aims of justification, e.g. believing the truth and believing what is
implied by one’s evidence.

That might be OK: it wouldn’t beg the question against Maitzen and Fumerton,
whose arguments could just as well be taken as arguments against truth being one
of several aims of justification.

But we might doubt that the proposed account really is committed to several
aims. After all, does ϕ-ing in order achieve aim A entail that one aims both at ϕ-ing
and achieving A?
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Conclusion
 I have argued for two main claims:
 That three popular intuitions in favor of the possibility of
justified false beliefs fail, at least as far as the relevant
sense of ‘justification’ is concerned.
 That an account of justification which requires that the
truth of the justified proposition is implied by the agent’s
evidence is less unpalatable than commonly supposed.
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Thank you!
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