Aquinas on Testimonial Justif ication:

Faith and Opinion

Sometimes we believe something on someone else’s testimony, rather than by seeing it

for ourselves. Testimony is important. Without it I would know nothing about distant

events, or about world history. I would know nothing about the middle ages. I probably

would not have any friends, since I would not be able to tell people what I was thinking,

and they would not be able to tell me what they were thinking. And I would not even

know who my own parents are, since I do not remember my birth. Without testimony,

we would know hardly anything about our family, friends, or country. It would be the

end of human society.

It is worth considering how we know these things, and the topic has garnered

much recent attention. In this paper I contribute to this discussion by reconstructing

Aquinas’s account of testimonial justification and contrasting it with some more recent

accounts. I also contribute to the history of philosophy by examining in some detail

Aquinas’s accounts of opinion and of human faith.

As I see it, Aquinas took a unique pluralist approach to testimonial justification.

One might be skeptical that Aquinas cared about this apparently newfangled

philosophical topic at all, so I begin by highlighting several ways in which everyday

testimonial “faith” was important to Aquinas (§I), and clarifying what he means by

“faith” (§II). Then I briefly describe three major approaches one can take in the

epistemology of testimony, which I call the Default, Inferential, and Interpersonal

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approaches (§III). I explain that Aquinas does not take a Default approach, but rather,

with regard to at least some cases of testimony, he takes an Inferentialist approach (§IV).

With regard to other cases of testimony he takes an Interpersonalist approach (§V) that

has certain advantages over recent Interpersonalist approaches (§VI). Aquinas’s overall

approach to testimonial justification is pluralist, in a way that avoids some common

problems for non-pluralist views (§VII).

I

The Christian tradition with which Aquinas was familiar often dealt with testimony under

the heading of “faith” (fides). And apologists in that tradition often drew attention to

instances of valuable testimonial belief in everyday life, to support the idea that by

analogy we ought to accept religious testimonial belief. For example, in the second

century Theophilus of Antioch said

Do you not know that faith [pistis] leads the way in all actions? … What sick man can be cured unless he first entrusts himself to the physician? What art or science can anyone learn unless he first delivers and entrusts himself to the teacher?1

In the same vein, Aquinas, in the course of arguing for religious faith, explains three

ways in which testimonial belief contributes to human society.

First, following Maimonides, Aquinas says that even when certain talented

individuals can demonstrate some important truth for themselves (e.g., that God exists),

the vast majority of people still need faith with regard to that truth, since most of them

will not have the time, talent, or training to perform such a demonstration.2 And some of

1 Theophilus of Antioch, Ad Autolycum, trans. R. Grant (Oxford: Clarendon Press, 1970), 1.8. 2 Thomas Aquinas, Quaestones disputatae de veritate (henceforth De veritate) q. 14 a. 10c (Leonine ed. 22); Super Boetium de Trinitate (henceforth In B. de Trin.) q. 3. a. 1c (Leonine ed. 50); Summa contra

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those who do have the time, talent, and training necessary will be lazy or make mistakes,

and so would be better off having faith anyway. Today we might similarly say that most

people must accept important claims of natural science, especially counterintuitive ones

about, say, special relativity or quantum indeterminacy, on “faith”.3 Call this a vertical

epistemic division of labor, extending from experts down to those who trust them.

Following Aristotle, Aquinas found a vertical division of labor among the experts

themselves, since often one science depends on another. Aquinas says that sometimes a

“lower” or “subalternated” science takes on “faith” the conclusions demonstrated by a

“higher” science.4 For instance, some theorems demonstrated in geometry are the

starting axioms of optics (a “lower” science), and when the optician does not know the

geometrical demonstrations for them, she must take them on faith from the geometers.

We see something similar today in the way biology depends on chemistry, and chemistry

on physics.

Second, Aquinas, like Augustine, argues that human society could not function

gentiles (henceforth SCG) I.4 (Leonine ed. 13); Summa theologiae (henceforth ST) I, q. 1 a. 1c (Leonine ed. 4); ST II-II q. 2 a. 4c (Leonine ed. 8). 3 W. V. Quine and J. S. Ullian, The Web of Belief, 2nd ed. (New York: Random House, 1978), 61-62. 4 In B. de Trin. q. 2 a. 2 ad 7: “The ultimate first principle of any science is always understanding (intellectus), but this is not always the proximate principle; rather, sometimes faith is the proximate principle of a science, as in the subalternated sciences, in which conclusions come proximately from faith in the things supposed from a superior science, but come ultimately from the understanding of the superior knower, who has certainty, through understanding, about the things [merely] believed [in the subalternated science]. And similarly the proximate principle of [theology] is faith, but the first principle is the divine intellect, which we believe. And yet the goal of our faith is that we come to understand what we believe, just as if a subordinate scientist [inferior sciens] were to learn the science of a superior scientist, such that things previously only believed would become understood and known”. All translations of Aquinas’s works are my own. The classic work on this topic is M.-D. Chenu, La théologie comme science au XIIIe siècle (Paris: J. Vrin, 1969), but see also J. Jenkins, Knowledge and Faith in Thomas Aquinas (Cambridge: Cambridge University Press, 1997), R. Pasnau, “Divisions of Epistemic Labour: Some Remarks on the History of Fideism and Esotericism” Continuity and Innovation in Medieval and Modern Philosophy: Knowledge, Mind, and Language. Proceedings of the British Academy 189 (Oxford: Oxford University Press, 2013), and J. Hawthorne’s criticism of Pasnau in the same volume. For further discussion in Aquinas, see especially Expositio libri Posteriorum 1 (henceforth In 1 Post.) lect. 15 and lect. 25 (Leonine ed. 1.2). Other relevant passages include In 1 Sent. prologue q. 3 a. 2 ad 2 (Mandonnet ed.), In 3 Sent. d. 24 q. 1 a. 2 qc. 2 ad 3 (Mandonnet ed.); De veritate q. 14 a. 9 ad 3; In B. de Trin. q. 2 a. 2 and q. 3 a. 1c; In 1 Post. lect. 17 n. 3 and lect. 41 n. 2; ST I q. 1 a. 2c; ST I q. 79 a. 9c; ST II-II q. 9 a. 2 ad 3.

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without a horizontal epistemic division of labor.

For example, singulars and contingents that are removed from our senses, such as the acts, sayings and thoughts of people, are such that they can be known to one human and unknown to another. And since in human community it ought to be that one person use another as himself when he is not self-sufficient, so it ought to be that he stand toward those things which another knows, and are unknown to him, the way he stands to those he knows himself. Thus faith, by which one man believes the sayings of another, is necessary in human interaction. It also is the “foundation of justice” as Cicero says in De Officiis [1.23], which is why no lie is without sin, since every lie detracts from this faith that is so necessary. (Super Boetium de Trinitate q. 3 a. 1c, Leonine ed. 50, henceforth In B. de Trin.)

Here Aquinas makes the general point that a well-functioning society often requires us to

act on what other people know, when not in a position to verify something for ourselves.

Third, later in the same passage, Aquinas argues that faith is necessary for learning

the sciences.5

But since by the power of those which we know last are known those which we know first, we must from the beginning have some knowledge of those things which are better known in themselves, which cannot happen except by believing another [credendo]. And we see this in the order of the sciences, since the science of the highest causes, namely metaphysics, comes last in a man’s knowing, and yet in the preamble sciences one must suppose certain things which in [metaphysics] are known more fully. Hence every science has suppositions that the learner must believe. (In B. de Trin. q. 3, a. 1c)

Here Aquinas says that some of the pre-existing knowledge required for learning a

science must be testimonial. He appeals to the Aristotelian ordering of the sciences, on

which metaphysics is the most fundamental but also the most obscure. Similar

considerations apply to contemporary natural science, in which physics is the most

fundamental but at the same time arguably the most difficult to understand. Someone

5 See also De veritate q. 14 a. 10c; In B. de Trin. q. 3 a. 1c; Lectura super Ioannem (henceforth In Ioh.) 8.4 (Vivès 19); SCG III ch. 152 n. 4 (Leonine 11); ST II-II q. 2 a. 3c (Leonine 8); Expositio et lectura super Epistolas Pauli (on Hebrews, lect. 11 n. 1, Vivès 21).

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setting out to study physics would not get very far without some direction on the basic

principles of force, motion, and matter, as physicists today understand them.6 The faith

of a student, unlike that of non-experts in a vertical epistemic division of labor, is a

provisional faith, supporting her education until she is an expert herself, and in the ideal

case she comes to understand why the principles she accepted at the beginning of her

education are true.

So here we have three areas in which Aquinas recognizes the importance of

testimonial belief, in the form of human “faith”: when it enables guidance (1) from

experts, (2) from peers who happen to know something you did not know for yourself,

and (3) from teachers. Our task will be to see how such faith works, and what, according

to Aquinas, makes such belief rational or epistemically justified.

II

First we will need to get clear about what Aquinas means by “faith”. Aquinas’s

terminology can be confusing, since he uses “faith” in both a very broad sense (explained

in this section), and a narrow sense (to be explained in §V). Following Augustine,

Aquinas says that faith in the broadest sense is just assent to the “unseen”, by contrast

with assent to what one sees to be true.7 “Seeing”, in this sense, has both psychological

and epistemic aspects. Psychologically, when one sees that p, one’s assent is automatic

6 Here is an illustration: A physicist friend of mine told me of a physics undergraduate who had spent ten years on his undergraduate degree, because he spent most of his time in the library double-checking everything his teachers told him. 7 “‘Faith’ properly speaking is when someone assents to those things which he does not see” (In 3 Sent. d. 23 q. 3 a. 4 qc. 3 expos.). Aquinas uses the term “assent” the way philosophers today use the term “belief”, while he typically reserves the term “believe” (credere) for the act of faith, either in the broad sense explained here, or in the narrow sense explained in §V.

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and involuntary.8 Epistemically, the idea seems to be that an object “seen” is as directly

accessible to the knower as possible, in as determinate a way as possible, so that none of

the features relevant to knowing that p remains unrepresented to the knower.9 These

features of seeing make one’s grasp of the object “fixed” and “determined to one”,10 and

in this sense “certain”.11 The fixedness or certainty of seeing derive from the natural fit

between the intellect and the evidentness of the truth, so they are not just psychological

but also epistemic features of the knower.

For example, right now I know, by seeing, that a brown cup is on the table near

me. The features of the cup and of the table which are relevant to me knowing that a blue

cup is on the table (the cup’s and the table’s shape, size, color, etc.) are evident to me,

making my belief determinate in a way it would not be if I had formed that belief merely

on the basis of some natural sign of the cup’s presence (e.g., its shadow); or on the basis

of an inductive argument that a brown cup must be on the table; or on the basis of

someone else’s assertion that a brown cup is on the table. Aquinas takes the distinction

between the seen and the unseen to be sharp. “[A]s soon as something begins to be

present or apparent, the object cannot fall under the act of faith,”12 but anything short of

8 In 3 Sent. d. 17 q. 1 a. 2 qc. 1c; ST I-II q. 17 a. 6c; ST II-II q. 1 a. 4c. 9 ST I a. 85 q. 3c. 10 De veritate q. 12 a. 1c; q. 14 a. 1c; ST I q. 12 a. 13 ad 3; ST II-II q. 2 a. 1 ad 3; q. 4 a. 1c. 11 “Certitude is nothing other than determination of the intellect to one: the stronger the determination, the greater the certitude” (In 3. Sent. d. 23 q. 2 a. 2 qc. 3c). Aquinas implies here and elsewhere (In 1 Post. lect. 1 n. 1 and lect. 41 n. 2; ST II-II q. 5 a. 4c and ad 2; ST II-II q. 70 a. 2c) that certainty comes in degrees. And Aquinas identifies three different kinds of certainty relevant to determination of the intellect: certitude of evidentness, when the object is seen; certitude of adhesion, when the will is fully determined to assent; and certitude of cause, when the cause of one’s assent is perfectly reliable or efficacious (as in the case of divinely infused Christian faith). Science has the certitude of evidentness, which divinely infused Christian faith lacks, but they both have the certitude of adhesion, and sometimes Aquinas says that Christian faith’s adhesion is stronger, due to its cause (In 3 Sent. d. 23 q. 2 a. 2 qc. 3 ad 1, ad 2; De veritate q. 14 a. 1c and ad 7; ST II-II.4.8c and ad 1). 12 De Veritate q. 14 a. 9c.

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seeing makes room for the assent of faith.13

Because the object is unseen, the assent of faith is not fully automatic, but

requires an act of will.14 In cases of seeing, assent is “natural” rather than voluntary, so

the only voluntary choice an agent can make is whether or not to attend to p sufficiently

to see it.15 But as soon as p is unseen,

the intellect assents not because it is sufficiently moved by its proper object, but by a choice [electionem] inclining toward [one proposition] more than [to its contrary]. (Summa Theologiae II-II q. 1 a. 4c)

So it is essential to faith that one’s assent is determined partly by the will. However, this

condition does not make Aquinas a crude doxastic voluntarist, since assent is not

commanded by the will alone, but by the will under the direction of one’s reason.16 So

faith is not just belief on a whim; it is a matter of managing one’s assent for the best of

the human as a whole, given that one does not see for oneself whether p.

Now let’s consider what makes testimonial assent to the unseen justified. We will

first consider kinds of testimonial justification (in §III), and then see how Aquinas’s

13 In 3 Sent.. d. 24 q. 1 a. 3 qc. 3 ad 3; In B. de Trin. q. 2 a. 1 ad 5; ST II-II q. 2 a. 9 ad 3. 14 See In 2 Sent. d. 7 q. 2 a. 2 ad 5; In B. de Trin. 3.1c; SCG 3.154.1; ST I q. 12 a. 13 ad 3; De veritate q. 12 a. 1c. 15 In 1 Sent. d. 17 q. 1 a. 4c; ST II-II q. 2 a. 9 ad 2. By saying that assent is “natural”, Aquinas does not mean it is “natural and easy”, as Eleonore Stump says in Aquinas (New York: Routledge, 2003), 362, but just that it a naturally automatic process, not subject to voluntary choice. Stump’s example of a mother who “finds herself assenting, whether she wants to do so or not, to the proposition that the judge dislikes her son’s performance” is not an example of seeing, but of strong opinion, akin to demon faith. I discuss demon faith in §V below. 16 ST I-II q. 17 a. 6c: “[R]eason reflects on itself, so it can also order its own act just as it orders the acts of other powers. Hence its act can also be commanded. But we can consider the act of reason in two ways. [1] First, with regard to its exercise, an act of reason can always be commanded, as when someone is told to pay attention, and use his reason. [2] Second, with regard to the object, notice two acts of reason. [2a] First, the act of apprehending the truth about something, which is not in our power, for it comes about through the virtue of some light, either natural or supernatural. So in this respect the act of reason is not in our power, and cannot be commanded. [2b] But the other act of reason is that it assent to what it apprehends. If things are apprehended to which the intellect naturally assents, like first principles, assent or dissent to such is not in our power, but in the order of nature, and so, properly speaking, is not under our command. But some things are apprehended which do not convince the intellect so much that one cannot for some reason assent or dissent, or at least suspend assent or dissent, and in such cases the assent or dissent is in our power, and falls under one’s command.”

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testimonial “opinion” (§IV) is like one, and his testimonial “faith” in a narrow sense (§V)

is like another, allowing him to avoid some problems for recent accounts of testimonial

justification (§VII).

III

Three different recent approaches to the justification of testimonial belief each posit a

unique kind of testimonial justification.17

On the Default view, you are entitled to believe the assertions of others by default,

i.e., provided there is no evidence against such belief. Defaultists often draw an analogy

between believing others’ testimony and believing your own memory: you are entitled to

believe its deliverances, provided there is no sign of dysfunction. Testimony, on this

view, is yet another knowledge-providing faculty, like memory or perception. One

advantage of this view is that it explains why we usually do not consciously deliberate

about whether to accept the testimony of others. One problem for this view is that it

seems to entitle hearers to believe any zany statement, so long as one has no evidence

against it.

Inferentialists, on the other hand, think you get testimonial justification only by

inferring that an assertion is true. For example, you might infer that it is raining in

Norway from your evidence that Hildegaard told you by phone that “It is raining”,

together with your evidence that she is sincere and competent to know whether it is

17 I here give a simplified survey of the growing literature on the epistemology of testimony. For fuller surveys, see Jennifer Lackey, “Knowing from Testimony”, Philosophy Compass 1 no. 5 (2006): 432-448; John Greco “Recent Work on Testimonial Knowledge”, American Philosophical Quarterly 49 no. 1 (Jan. 2012): 15-28; Axel Gelfert, A Critical Introduction to Testimony, (New York: Bloomsbury, 2014).

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raining or not. One advantage of this view is that it explains testimonial knowledge in

terms of other kinds of justification that contemporary epistemologists are already

familiar with. One problem for this view is that it seems to leave no room for deciding to

trust a speaker, something that intuitively, we are capable of doing.

There is an important debate in the epistemology of testimony between

“reductionists” who claim that testimony does not provide a distinctive, or sui generis,

kind of justification, and “anti-reductionists” who claim it does. A standard way to be a

reductionist is to be an Inferentialist, like David Hume, and so reduce testimonial

justification to a species of inferential justification.18 In contrast, a standard way to be

anti-reductionist is to be a Defaultist, like Thomas Reid, and argue that we have a default

entitlement to believe others’ testimony.19

Recently another anti-reductionist approach has emerged. On an Interpersonal

view, one has properly testimonial justification only when the interpersonal relationship

between speaker and hearer provides the hearer with a non-inferential reason to believe

the speaker.20 For example, when a knowledgeable speaker offers me her “assurance”

that p, and I “accept” her assurance, then I am justified in believing p, without having to

infer that p for myself, and without having a default entitlement to believe what any old

speaker tells me. Just as promises are intentional offers to take responsibility for the

hearer’s well-being, assurances are intentional offers to take responsibility for the

18 See David Hume, An Enquiry Concerning Human Understanding, ed. Eric Steinberg (Indianapolis: Hackett, 1993), 2nd ed., chapter 10. On externalist reductionist views, see T. Simpson, “Review of Testimony, Trust, and Authority, by Benjamin McMyler and Knowledge on Trust, by Paul Faulkner” Mind 122, no. 485 (2013): 305-311. 19 See Thomas Reid An Inquiry into the Human Mind, ed. Derek Brookes (University Park: Pennsylvania State University Press, 1997), chap. 6, section 24. 20 For example, see Benjamin McMyler, Testimony, Trust, and Authority (Oxford: Oxford University Press, 2011), henceforth McMyler Testimony, Trust, and Authority. See also Jennifer Lackey’s criticism of such views in Learning from Words (Oxford: Oxford University Press, 2008), chapter 8.

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hearer’s belief being true. Accepting such an assurance from a responsible speaker gives

the hearer a right to believe that p without taking precautions she would otherwise take

against being mistaken about p, and a right to defer to the speaker challenges about how

belief that p is justified. One advantage of this view is that it explains the reactive

attitude of betrayal we have when we find out that someone assured us of something

false. One problem for this view is that it seems to say that when no assurance has been

given, for example to an eavesdropper or to a jury, the eavesdropper’s or the jury’s belief

is not testimonially justified, properly speaking, because not based on a special

interpersonal relationship.

IV

At first glance, one might think that of these three views, Aquinas takes the Default

approach. Aquinas says we are naturally designed to depend on others’ testimony,21 and

this suggests a natural entitlement to believe others by default.22 Aquinas does not

explicitly endorse such a view, but one might think that his rule that one ought to

“presume the good” of others until one knows otherwise implies a default entitlement to

believe others’ testimony.23 Aquinas says you should presume that others are not

sinning, so when someone speaks, your default presumption should be that she is not

lying. It is a bit tricky to get from this to the presumption that others are telling us the

truth, but let’s suppose for the sake of argument that there is a way to draw this

21 See In B. de Trin. q. 3 a. 1c quoted in §I above, and ST II-II q. 109 a. 3 ad 1. 22 I am grateful to Martin Pickavé for pointing out this line of thought. 23 ST II-II q. 60 a. 4c: “[F]rom the fact that someone has a bad opinion of someone [else] without sufficient cause, he does him an injustice and despises him. But no one ought to despise or bring about whatever harm without being forced to [absque causa cogente]. So where no manifest signs of malice in someone appear, we should take him to be good, interpreting for the best [in meliorem partem] what is doubtful.”

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conclusion from what Aquinas says.

Nevertheless, Aquinas is talking here about presumption, not belief or assent. A

jury is not required to believe the defendant is innocent, but just to presume that she is.

Further, such a presumption aims not at the epistemic goal of producing the most

accurate belief, but at the practical goal of causing the least harm to others, and applies

only where there is room for reasonable doubt about how to judge the case.24 So

“presume the good” is a moral, not an epistemic rule. Thus, whether one ought to

suspend one’s presuming the good of others depends not on whether it would lead to a

cognitive error, but on whether it would endanger someone else.25 In short, the rule is not

about epistemic justification, and so does not support a default entitlement view of

testimonial justification.

In fact, there is good evidence that Aquinas thinks that at least some of the time

our testimonial beliefs are justified not by default but by inductive inference. He says

that “to believe a human without probable reason is to believe too quickly”26, and that in

important matters (like faith and morals), “assent ought not to be given easily”.27

In particular, Aquinas recognizes a specifically inferential way of arriving at

testimonial beliefs, which he calls “opinion”. One way to have faith (i.e., to assent to the

unseen), he says, is when one is “led [to assent] by human reason, and so strong opinion

24 See ST II-II q. 60 a. 4c and In Ioh. 2.3. In addition, presuming the best takes two forms, neither of which is a case of outright belief. Either one “supposes” the best of another to avoid the injustice of contempt (just as one “supposes the worst” in a medical case in order to make sure of a cure), or one “determines” a case where one’s evidence is incomplete (like a judge deciding a case) (ST II-II q. 60 a. 4 ad 3). 25 ST II-II q. 70 a. 3 ad 2: “One should presume good of everyone unless the contrary is apparent, so long as it does not tend toward anyone’s danger; for then one should apply caution that one not believe anyone easily.” ST II-II q. 60 a. 4 ad 1: “It can happen that he who interprets for the best is deceived rather often [frequentius fallitur]. But it is better that someone be deceived frequently, having a good opinion of some bad man, than that he be deceived less often, having a bad opinion of some good man, because in the latter case he does an injustice to someone, but not in the first.” 26 In 3 Sent. d. 24 q. 1 a. 3 qc. 2 ad 1. 27 Quodlibeta 3 q. 4 a. 2c (Leonine ed. 25).

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is called ‘faith’.”28 (Here strong opinion contrasts with other cases of opinion in which

one does not give full assent, and so does not believe.29) What does Aquinas mean by

“opinion”? Opinion is essentially a matter of inductive or “probable” inference based on

“signs”, “verisimilitudes”, or “probable” (i.e. non-demonstrative) syllogisms.30 Aquinas

contrasts opinion with cognitive propositional habits (or as we say today, propositional

attitudes) that have lower credence than opinion: suspicion is a slight inclination to

assent to p, and doubt is an equal inclination to assent to p and to not-p.31 Further,

opinion that p involves an awareness that not-p is possibly true.32 So opinion that p is,

roughly, taking p to be probable by inductive inference. A testimonial case of opinion

comes up while Aquinas is contrasting opinion with the comprehension of science:

If someone knows by demonstration that a triangle has three angles equal to two right angles, he comprehends it, but if someone else accepts his opinion in a probable way [opinionem accipiat probabiliter], because it is said by the wise or the many, he does not comprehend it, because he does not attain the perfect way of knowing it as far as it is knowable. (Summa theologiae I q. 12 a. 7c)

Here we have testimonial assent based on a dialectical syllogism such as:

If most people say that p, then probably p. Most people say that p Therefore p.

Aquinas recommends such reasoning in the case of court testimony. Other things being 28 In 3 Sent. d. 23 q. 3 a. 4 qc. 3 expos. 29 Aquinas sometimes glosses strong opinion as opinion “helped by reasons” (In B. de Trin. q. 3 a. 1 ad 4) or “strengthened by reasons” (In 1 Sent. prologue q. 1 a. 3 qc. 3 ad 1). I discuss strong opinion further in §V below. 30 In 1 Post. lect. 1 n. 6 is Aquinas’s fullest discussion on the way opinio is justified, but see also the way he contrasts it with science in In 1 Post. lect. 44; ST I-II q. 51 a. 3c; In 3 Sent. d. 17 q. 1 a. 2 qc. 1c, and In B. de Trin. q. 3 a. 1 ad 4. 31 ST II-II q. 2 a. 1c, In 1 Post. lect. 1. 32 Aquinas calls this “fear of the contrary”, and says that “it is of the nature of opinion that what one thinks, one thinks possible to be otherwise” (ST I-II q. 67 a. 3c; ST II-II q. 1 a. 5 ad 4). The “faith or opinion” of In 1 Post. lect. 1, I suspect, is identical with what Aquinas elsewhere calls “strong opinion” (see §IV and §V below). On this topic, see Martin Pickavé, “Human Knowledge” in The Oxford Handbook of Aquinas, ed. E. Stump and B. Davies (Oxford University Press, 2012): 325, n.30; and F. Tyrrell, The Role of Assent in Judgment: A Thomistic Study (Washington: Catholic University of America Press, 1948): 87.

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equal, we should give more weight to p when more witnesses say p than not, because “it

is probable that the saying of many contains the truth more than the saying of one”.33

In brief, Aquinas recognizes inferentially justified assent in the form of opinion;

he recognizes that some inferentially justified assent (namely, strong opinion) is outright

belief; and he recognizes that some opinion is testimonial. So he has all the resources to

provide an inferential account of at least some cases of testimonial belief.

V

However, Aquinas also recognizes cases of testimonial belief justified in an Interpersonal

way. The most striking case, and the one he elaborates on most fully, is a Christian’s

faith in God. But Aquinas also describes analogous cases of faith on the testimony of

fellow humans, where the justification of one’s beliefs is similarly Interpersonal. In this

section, we will consider the formal object of faith, the special act of will in faith, and a

typical reason for having faith. In the following section we will contrast such faith with

demon faith and with the Interpersonal forms of justification posited by some recent

accounts of testimonial justification.

Faith in the broadest sense (assent to the unseen) includes strong opinion. But

from now on, I will use the term “faith” in the narrower Interpersonal sense, as Aquinas

usually does, to contrast it with opinion.34 Three features of Christian faith in God, and

of the analogous case of faith in one’s fellow humans, distinguish faith from opinion.

33 ST II-II q. 70 a. 2c. 34 For the view that faith is opinion, see Thomas Hobbes, Leviathan, ed. C. B. Macpherson (London: Penguin Books, 1968): 1.7. For the view that believing a speaker is merely a matter of probability, see John Locke, An Essay Concerning Human Understanding, ed. Roger Woolhouse (London: Penguin Books, 1997): Book IV, chapter xv.

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When one has faith that p, one (i) believes the speaker’s statement in order to adhere to

the speaker, (ii) with a special act of will not present in opinion, (iii) typically for the

reason that the speaker is truthful. Let’s look at these three features in turn.

First, faith responds to the person of the speaker as a reason to believe. This

feature is the most obscure of the three, and explaining it will take up most of our

discussion. It comes up first in Aquinas’s discussions of faith as an act of believing God

(credere Deo). Augustine had a way of making catchy philosophical distinctions in

passing, and Peter Lombard then offered many of these up for scholastic interpretation in

his Sentences. One of them is a distinction between three different objects of the act of

belief in faith: credere Deum (“believing that God [exists]”),35 credere in Deum

(“believing in God”), and credere Deo (“believing God”). Aquinas assigns each of these

acts to a different part or combination of parts of the soul. Credere Deum is the

intellect’s act of being determined to the one proposition believed. Credere in Deum is

the will’s act of believing out of love of God, where the will’s object is God himself.

Credere Deo (“believing God”) is reason’s act of inclining the will to assent, where the

object is the proposition believed, but only as spoken by that speaker:

Inasmuch as reason inclines the will to the act of faith, it is credere deo. For the reason the will is inclined to assent to things unseen is because God said them; just as a man, in matters he does not see, believes the testimony of some good man who sees the things he does not.36

Aquinas here identifies a reason for belief (“because God said them”) that he considers

not reducible to an inductive reason for belief of the kind that supports testimonial

opinion. Assent is not Christian faith when the proposition is believed

35 “Credere deum” refers to all the propositions believed on faith, not just the proposition that God exists. In 3 Sent. d. 23 q. 2 a. 2 qc. 2c; ST II-II q. 2 a. 2c. 36 In 3 Sent.d. 23 q. 2 a. 2 qc. 2c; In B. de Trin. q. 3 a. 1 ad 5.

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by some human reasons and natural signs … but only when one believes for this reason [ratione], that it is said by God, which is designated by calling it credere Deo. And this specifies faith, the way any cognoscitive habit has its species from the reason [ratione] by which it assents to anything.37

Here “reason” (ratione) need not signal that the believer is drawing an inference. Not all

cognitive habits of propositional assent (or propositional attitudes) result from a

reasoning process; some, such as prophecy,38 or intellection of first principles,39 are not

mediated by reasoning. Nevertheless, every cognitive habit has a “ratio” in the sense that

it has a distinctive character that distinguishes it from other cognitive habits. So here

Aquinas is saying that one has Christian faith only when one believes something in light

of this, that it is said by God. Aquinas calls the distinctive character of a habit its “formal

object”, and contrasts the character of faith with inferentially based habits like opinion

and science.

In Aquinas’s view, every power, habit, and act has both material objects – the

items it is directed at – and a formal object – the formal aspect of those items that allows

that power (or habit or act) to be directed at them.40 For example, my will is right now

directed at a ripe mango as material object, but according to Aquinas my will can be

directed at that mango only insofar as I apprehend the mango as good.41 And that same

mango can be a material object for various other powers, under other formal aspects, by

37 Expositio et lectura super Epistolas Pauli Apostoli (part on Romans, lect. 4 n. 1, Vivès 21). 38 De veritate q. 12 a. 1c; ST II-II q. 171 a. 1c. 39 ST I-II q. 57 a. 2c; I-II q. 51 a. 3c; II-II q. 4 a. 8c; In 1 Post. lect. 4 n. 8. See also In 2 Post. lect. 20, but on the induction involved in intellection of first principles see Scott MacDonald, “Theory of Knowledge” in The Cambridge Companion to Aquinas ed. N. Kretzmann and E. Stump (New York: Cambridge University Press, 1993): 183, 194-5. 40 In 3 Sent. d. 27 q. 2, a. 4 qc. 1 ad 3: “Material diversity of objects suffices for distinguishing acts numerically, but they are not distinguished according to species except by diversity of formal objects. But the diversity of formal objects is according to the notion which a habit or power principally attends to …”. ST I q. 59 a. 2 ad 2: “Powers are not distinguished by a distinction of material objects, but by a formal distinction, following the notion of the object. And thus a notional diversity of good and true suffices for distinguishing intellect from will” 41 ST I q. 59 a. 4c; I-II q. 8 a. 1c; I-II q. 9 a. 1-2.

16

being visible, movable, understandable, etc. It can also be a material object for different

kinds of willing, more specific than willing in general, as distinguished by different

formal aspects under which the mango is good (e.g., good as tasty, as opposed to good as

nourishing).

The intellect is a single cognitive power aimed at the truth, but different ways of

grasping the truth make for different formal objects and so make for different habits. Just

as the same mango can be the material object of different kinds of willing, so the same

proposition can be the material object of different cognitive habits (or propositional

attitudes). And while these different ways of assenting provide different explanations of

or “reasons” for one’s belief, not all of them are cases of inferential reasoning. For

example, Aquinas would distinguish between the way my geometer friend Joe believes

the theorems of geometry as self-evidently following from self-evidently seen first

principles, and the way I believe those theorems when I take them on faith from Joe. Joe

starts from axioms which he simply sees to be true, without any inferential reasoning,42

and then on that basis reasons his way to the theorems. But when I take those same

theorems on faith from Joe, I neither see that they are true for myself, nor reason my way

to believing them. Rather, I believe Joe, and only thereby come to believe that those

theorems are true. So the “material objects” of my faith are propositions (the same

theorems Joe knows), while the “formal object” of my faith is believing the speaker (in

this case, Joe), just as the Christian with faith believes God (credere Deo).

Elizabeth Anscombe also talks about believing the speaker, and distinguishes that

42 See note 32 above.

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act of faith from the act of merely believing what the speaker says.43 When you tell me

something I already knew (e.g. “George Washington was the first president of the United

States”), I believe what you say, but not by believing you. When you present me with a

mathematical proof that every integer is the product of its arithmetic mean and harmonic

mean, and I follow the proof to its conclusion, I come to believe what you say (the

premises and the conclusion), but not by believing you.

Opinion similarly is a matter of believing what the speaker said, but not by

believing the speaker. Suppose our chemist friend Sal hypnotizes you to say “Mercuric

oxide bonding is endothermic” the next time we meet, and when you say it, I infer that

you said it because Sal so hypnotized you, and on that basis infer that the statement is

true. My probable inference gives me an opinion that your statement is true. So I believe

what you said, but not by believing you. Or suppose you know that I do not trust you, so

you try to mislead me by saying something true, in the expectation that I will not believe

you; but I see through your ruse and infer that what you say is true. In such a double-

bluffing case, I believe what you say, but not by believing you. These cases are far-

fetched, but they help us draw the negative point that believing the speaker is not opinion.

Aquinas also has a positive account of what it is to believe the speaker, one that

further explains how it differs from opinion. He says faith is had by “adhering” to the

speaker.

On the part of the intellect, there are two ways to take the object of faith. One is the material object of faith. … Another is the formal object, which is like a means [medium] on account of which one assents to such a credible [proposition]. In this way the act of faith is called credere Deo, because, as

43 Elizabeth Anscombe, “What Is It to Believe Someone?” in Rationality and Religious Belief, ed. C. F. Delaney (Notre Dame: Notre Dame University Press, 1979): 144-145. We might find a similar distinction at work in ST II-II q. 129 a. 6c, where Aquinas says “it pertains to faith to believe something and someone”.

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said above, the formal object is the First Truth [i.e., God], to which a man adheres so as, on account of it, to assent to what he believes. (Summa theologiae II-II q. 2 a. 2c)

The assent of different propositional cognitive habits (or propositional attitudes) is

produce by different means: opinion is produced by inductive inference, science by

demonstration, and faith by adherence to the speaker. Aquinas explains adherence further

by an analogy:

Since whoever believes assents to the word of someone, it seems that the principal thing in any believing44, like an end, is the person to whose word one assents, while the items one believes in order to assent to that person are secondary. (Summa theologiae II-II q. 11 a. 1c)

Assent to a proposition stated by a speaker is like a means to the end of adhering to that

speaker.

Nowadays we sometimes use the word “faith” to refer to a kind of trust, as when I

say that I have faith that my friend will pay me back; and we sometimes use “faith” to

refer to a kind of loyalty, as when I say that I have kept faith with my friend. Aquinas’s

talk of adherence, I suggest, combines these notions of faith as trust and faith as loyalty.

Aquinas treats faith as trusting belief out of loyalty to the speaker. By contrast, opinion is

just a matter of taking something to be probable on one’s own evidence, without regard

for adhering to the speaker. The loyalty and trust of faith are ways of depending more

extensively on a speaker for the truth than one would on opinion alone. For example,

faith is incompatible with taking certain precautions against the speaker being wrong,

44 Note that in this context “believing” refers specifically to the act of faith in a narrow sense (ST II-II q. 2 a. 1ff), not to the assent that can also be found in other cognitive habits like knowledge from demonstration or opinion from inductive inference.

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whereas opinion is not.45 Thus, the attempt to establish one’s opinion on some matter of

faith by considering all the evidence (or even enough evidence to judge the matter for

oneself) is in effect an attempt to replace faith with either opinion or seeing. This can be

good, epistemically speaking, as when a student moves from relying on her teacher to

knowing something for herself. But it can also be bad, as when one is unjustifiably

suspicious of some expert’s claim that p merely because p seems improbable on one’s

own scanty evidence.

We have considered the first feature that distinguishes faith from opinion: faith’s

formal object as a means to assent, that is, believing a statement in order to believe the

speaker in the sense of adhering to the speaker. Now let’s consider the second feature:

the choice of faith.

Faith is specially creditable to the believer as something she chooses, whereas

opinion and science are not. Aquinas contrasts faith in this regard with both opinion and

science. In the case of science, assent is “forced” (cogitur), while opinion “does not have

firm assent” and so “does not much seem to have merit” (non multum videtur habere

rationem meriti). The assent of faith, by contrast, is subject to free choice, and so can be

meritorious.46 Another time Aquinas draws this contrast with both opinion and science,

he says that in the case of faith the will can

choose to assent to [a proposition] determinately and distinctly because of something sufficient to move the will, but not to move the intellect; for example, because it seems good or fitting [bonum vel conveniens] to assent to it. And this is the disposition of belief,47 as when someone believes the sayings of some human, because it seems to [the audience] appropriate or

45 See Arnon Keren, “Trust and belief: a preemptive reasons account” Synthese (pre-print online, 2014), henceforth “Trust and belief”, for an account of testimonial trust on which trust requires seeing oneself as having a reason not to take precautions against the speaker’s testimony being false. 46 ST II-II q. 2 a. 9 ad 2. 47 Here again “belief” refers specifically to the act of faith. See note 44 above.

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beneficial [decens vel utile].48

Demonstration forces assent, while opinion, I suggest, gives assent no more than is

required by the evidence.49 Even strong opinion is stronger only in response to one’s

evidence. So neither science nor opinion has the special merit of faith.

This last passage indicates that, even if faith is not inferential, it still requires a

reason or explanation for it seeming good to the audience to adhere to the speaker. One

such reason that Aquinas points to is the audience’s recognition of the truthfulness of the

speaker. And this is our third distinguishing feature of faith, that a typical motivation for

faith is that the speaker is truthful. In the case of Christian faith, Aquinas does frequently

say that one believes God because of God’s truthfulness (or because God cannot lie).50

Elsewhere, he says that a good reason for believing a human speaker is the speaker’s

conscientious veracity,51 and that when we consider whether to have religious faith, even

miracles “do not prove [the propositions of] faith directly, but prove the truthfulness of

those announcing the [propositions of] faith”.52 These passages seem to refer to the

Aristotelian virtue of truthfulness (veritas or veracitas). Truthfulness is a moral virtue of

accurate self-representation (avoiding the extremes of boasting and self-deprecation). It

is motivated by a love of truth, and falls under the virtue of justice, because it is oriented

toward giving others the truth.53 And just as a minimum degree of friendliness and

pleasantness is required for the proper functioning of society, so is a minimum degree of

48 De veritate q. 14 a. 1c. 49 The passage just quoted is in tension with ST II-II q. 1 a. 4c, where Aquinas says that even opinion involves a “choice”. I suggest that the “choice” involved in opinion (ST II-II q. 1 a. 4c) is merely a choice to assent to the degree justified inductively on one’s own evidence, and is fairly automatic. 50 Expositio et lectura super Epistolas Pauli Apostoli (part on 2 Timothy, lect. 1 n. 4, and part on Galatians, lect. 6 n. 2, Vivès 21); ST II-II q. 2 a. 4c; ST II-II a. 5 q. 2c; ST II-II q. 89 a. 1c. 51 In 3 Sent d.23 q. 3 a. 4 qc. 3expos. 52 In 3 Sent. d. 24 q. 1 a. 2 qc. 2 ad 4. 53 For Aquinas on truthfulness, see Sententia libri Ethicorum lib. 4 lect. 15 (Leonine ed. 47); ST I q. 16 a. 4 ad 3; ST II-II q. 109.

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truthfulness.54 Without it, the epistemic divisions of labor by which one believes experts,

peers, and teachers, would collapse.55 Aquinas goes beyond Aristotle by noting that as a

virtue of accurate self-representation, truthfulness concerns the particular case of

accurately representing one’s knowledge.56 The truthfulness of a speaker thus contributes

to the rationality of one’s faith by putting one in touch with a speaker’s knowledge.

Unlike opinion, which restricts one to one’s own evidence, faith in a truthful

speaker allows one to “share” and be “joined” to the knowledge of the speaker.57 Thus

faith makes one’s belief more sensitive to a truthful speaker’s evidence, and less sensitive

to one’s own evidence.58 So when presented with a knowledgeable and truthful speaker’s

statement, the audience that restricts itself to inferring from its own evidence will be less

certain and have worse epistemic standing than an audience that has faith. For example,

suppose both Fay and Opie are told by their friend Knox that the fastest way to the CN

tower is to take the second highway exit after the tower. They both assent, but Fay has

faith while Opie has opinion. As they separately drive there, they each see what looks

like a much more direct route. Opie might either change his mind, or at least be more

ready to change his mind than Fay. So if Knox does know the way, Fay is in a better

epistemic position than Opie. If, on the other hand, Knox is wrong and does not know

54 ST II-II q. 114 a. 2 ad 1. 55 In ST II-II.109.3 ad 1, Aquinas says this of social dependence for the truth generally, but does not cite the three epistemic divisions of labor mentioned in In B. de Trin. q. 3 a. 1 which I discussed in §I above. 56 ST II-II q. 109 a. 3 ad 3: “But since knowable truths, inasmuch as they are known by us, are about us and pertain to us, in this way the truthfulness [veritas] of teaching can pertain to this virtue, and whatever other truthfulness [veritas] by which one manifests by word or deed what one knows.” 57 Aquinas says that Christian faith joins us to the God’s knowledge in De veritate q. 14 a. 8c; SCG 1.4; ST I q. 1 a. 1c. 58 ST II-II q. 4 a. 8 ad 2: “Other things being equal, vision is more certain than hearing. But if [the authority] of the speaker greatly exceeds the vision of the seer, then hearing is more certain than vision. Someone of little knowledge is made more certain [magis certificatur] about something he hears from someone extremely knowledgeable [scientissimo] than about something seen by his own reason. And man is much more certain about what he hears from God, who cannot be deceived, than about what he sees with his own reason, which can be deceived.” See Keren “Trust and belief”, 20-21, on the way trust makes one “less sensitive to evidence available to one” but “more sensitive to evidence available to the speaker”.

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the way, then Opie can blame only himself for his mistaken inference, whereas Fay can

also blame Knox for breaking faith with her by not being truthful.59 Faith has the

drawback of making one dependent on the speaker, but it also has the benefit of linking

one’s justification to that of the speaker in a way that inductive inference does not. This

is because faith is not merely a very strong inferential belief that p, supported by a

premise about the truthfulness of the speaker, but rather a way of assenting to what a

speaker says by means of adhering to that speaker.

VI

Aquinas does not stick to such humdrum examples as these. His contrast is between

demon faith (a kind of strong opinion) and Christian faith. Imagine that a demon sees a

prophet make a prediction and perform a miracle (raising a corpse to life) as a sign that

God confirms his prediction. Realizing that such a miracle could have been performed

only with God’s power and permission, the demon unwillingly infers with near certainty

that the prophet’s prediction will come true.60 But the demon does not see that it will,

since only God sees the future,61 so the demon’s assent is still assent to the unseen, and so

is still a case of faith in the broad sense (the sense of “faith” explained in §II). Demons

are smarter and more knowledgeable than we are, and have more experience with

59 To be more precise, Opie can blame both himself for his mistaken inference and Noel for undermining the minimal faith (in yet another sense of “faith”, namely, trustworthiness, In 3 Sent. d. 23 q. 3 a. 4 qc. 3 expos.) required for the good functioning of society (In B. de Trin. q. 3 a. 1c; ST II-II q. 109 a. 3 ad 1). Fay, on the other hand, can fully blame Noel, unless for some reason she should not have taken Noel to be a truthful person (at least on the subject at hand). For a similar distinction, see Miranda Fricker, “Group Testimony? The Making of a Collective Good Informant”, Philosophy and Phenomenological Research 84 no. 2 (2012): 257, on the difference between “ethical let-down” (appropriate for Opie to feel when Noel is wrong about something he said) and “betrayal” (appropriate for Fay to feel when Noel is wrong about something he assured her of). 60 ST II-II q. 5 a. 2c. 61 ST I q. 86 a. 4c. See also In 2 Sent d. 7 q. 2 a. 2c; De veritate q. 8 a. 12c and ad 3; De veritate q. 12 a. 10c; SCG I.63.5; ST I q. 57 a. 3c; Quaestiones disputatae de malo q. 16 a. 7c (Leonine ed. 23).

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prophetic predictions, so alternative explanations of the miracle and its relation to the

prophet’s prediction that a human might consider are not open to the demon: demon faith

is super-strong testimonial opinion which compels assent “by the evidentness of signs”62

and “by the perspicacity of [the demon’s] natural intellect”.63 The Christian who does

not see the miracle, by contrast, has to trust God’s message and His messenger. So there

is still room for the human to believe by a special act of will, out of loyalty to the

speaker.64

Here a puzzle arises. In §II we noted that seeing compels belief, but that the unseen

leaves room for the will (under the influence of reason) to command belief. This is true

even in the fairly automatic case of opinion. So can belief in something unseen be

“compelled” by the evidence?65 This puzzle dissolves when we see that opinion can be

compelled, but not in the way that seeing is compelled. Ordinary opinion might yield no

assent or weak assent, but strong opinion is based on arguments or signs strong enough to

minimize one’s fear of not-p, and so convince one that p.

Whenever things accepted are in some way assented to, there must be something that inclines one to assent: in assent to per se known first principles, it is a naturally endowed light … and in assent to what we opine, some verisimilitudes, which, if they were a little stronger, would incline one to believe, as opinion helped by reasons is called “faith”. (In B. de Trin. q. 3 a. 1 ad 4)

62 De veritate q. 14 a. 9 ad 4: “The demons do not assent voluntarily to the things they are said to believe, but are coerced by the evidentness of signs [sed coacti evidentia signorum], from which they are convinced that what the faithful believe is true, although those signs do not make visible what is believed so that through them they could be said to have vision of the things they believe. Thus ‘credere’ is said almost equivocally [quasi aequivoce] of faithful humans and of demons.” 63 ST II-II q. 5 a. 2 ad 2. 64 An similar case for Aquinas is the case of the disciple Thomas, who both saw Jesus resurrected and had faith in him. Aquinas says that “Thomas saw one thing and believed another. He saw [Jesus] the human and, believing, confessed him God, when he said ‘My lord and my God’”, Summa Theologiae II-II q. 1 a. 4 ad 1. 65 Terence Penelhum, “The Analysis of Faith in St. Thomas Aquinas”, Religious Studies 13 no. 2 (1977): 133-154, draws attention to this puzzle.

24

Aquinas’s idea seems to be that evidence can provide one with grounds for believing that

are sufficient for passing a credence threshold, such that one becomes “convinced”.66

Assent can then be compelled, even though p remains unseen, “by the fact that nothing to

the contrary is apparent”.67 So even if the demon does not see that p, it might see that all

possible alternatives to p are so improbable that assent to p is clearly the only reasonable

option. In a sense, then, it is compelled to assent by the evidence.

Now that we have examined three features of testimonial faith (adherence to the

speaker as formal object, the choice of faith, and truthfulness as a reason to have faith),

and considered a few examples, we are in a position to compare Aquinas’s account of

faith with some contemporary Interpersonal accounts of testimonial justification. Unlike

several recent philosophers inspired by the ordinary language analyses of J. L. Austin and

H. P. Grice,68 Aquinas does not focus on the speaker’s role, or the specific speech act of

“telling” by which a speaker takes responsibility for the justification of an audience’s

beliefs. At most, Aquinas focuses on the speaker’s virtue of truthfulness as a reason for

the audience to adhere to the speaker in a way that makes inductive inference with regard

to p unnecessary. In this regard, Aquinas’s account is more like Arnon Keren’s or Linda

Zagzebski’s account of epistemic authority as a “preemptive” reason to believe what an

66 Aquinas seems to use “be convinced” to mean “give full assent to”, as when he says that “there can be something active that totally overcomes the corresponding passive power, as when one per se nota proposition convinces the intellect to assent firmly to a conclusion” (ST I-II q. 51 a. 3c). See also ST I-II q. 17 a. 6c. He says that in faith one is so “convinced” in ST II-II q. 4 a. 1c; De veritate q. 14 a. 2 ad 14; In Heb. 11.1. 67 In 3 Sent d. 23 q. 3 a. 3 qc. 1c. 68 See, for example, Richard Moran, “Getting Told and Being Believed”, Philosopher’s Imprint 5 no. 5 (2005): 1-29; Edward Hinchman, “Telling as Inviting to Trust”, Philosophy and Phenomenological Research 70 no. 3 (2005): 562-87; Benjamin McMyler, Testimony, Trust, and Authority; Paul Faulkner, Knowledge on Trust (Oxford: Oxford University Press, 2011): chapter 6.

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epistemic authority believes.69 A “preemptive” reason to believe is a reason to believe

what the authority tells you, together with a second-order reason not to base one’s belief

on certain other evidence that may be available to you.70 A preemptive reason “replaces”

certain other evidence you have, such that you defer to the authority on the question of

what you ought to believe, the way a soldier defers to the commanding officer on the

question of what to do. The main similarity between such accounts and Aquinas’s

account of faith is that taking someone to be an epistemic authority as a preemptive

reason to believe makes your belief more sensitive to the speaker’s knowledge, just as

Aquinas’s testimonial faith does, and less sensitive to your own evidence. But Aquinas’s

account of faith is distinctive in the role it gives to adherence. And Aquinas’s idea that a

speaker’s truthfulness can be a reason to have faith gives him a distinctive virtue account

of testimonial trustworthiness that is worthy of further investigation.71

Most recent epistemologists of testimony, even when they discuss trust, say little

about testimonial trustworthiness. The standard approach is to say that a trustworthy

speaker is just one who is both sincere and competent on the topic at hand.72 Judging a

speaker sincere and competent in this way gives good support for testimonial opinion that

what the speaker says is true. But a non-virtuous speaker can be sincere and competent

on some occasion, while nevertheless not being worthy of an audience’s faith. This is 69 See Linda Zagzebski, Epistemic Authority: A Theory of Trust, Authority, and Autonomy in Belief (Oxford: Oxford University Press, 2012): especially chapters 5-7 and 9 (henceforth Zagzebski, Epistemic Authority); Keren “Trust and belief”. 70 I take part of this formulation of a preemptive reason from Keren “Trust and belief”: 8. 71 I argue in more detail that testimonial trustworthiness is Aristotelian truthfulness in [*citation removed]. 72 See, for example, Elizabeth Fricker, “Telling and Trusting: Reductionism and Anti-Reductionism in the Epistemology of Testimony”, Mind no. 104 (1995): 393-411; McMyler, Testimony, Trust, and Authority: 93-94. Katherine Hawley, “Trust, Distrust and Commitment” Nous 48 no. 1 (2014): 1-20, has a more nuanced account of testimonial trustworthiness, but I argue elsewhere that for reasons similar to the ones I give below she fails to provide a sufficiently virtue-based account of trustworthiness to licence the kind of trust required for testimonial faith. Zagzebski, Epistemic Authority, chapter 6, comes closest to Aquinas in this regard, by requiring not just “sincerity” and “accuracy” of belief for testimonial trustworthiness, but “conscientious” sincerity and accuracy.

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true, for example, of a terrorist who knows where his comrades are hiding and sincerely

tells his interrogator where they are, under torture. Sincerity can be compelled by such

things as threats, torture, and hypnosis. Even competence on a topic can be compelled by

hypnosis, and could conceivably be compelled in science-fictional cases by brain lesions

or brain-controlling devices. Because speakers compelled in these ways do not speak the

truth freely out of a virtuous motivation, they are not worthy of the audience’s faith.

Truthfulness, by contrast, is a virtue and provides a good reason for faith. Truthfulness is

also a more fundamental reason to have faith than epistemic authority, since truthfulness

governs how a speaker represents her knowledge to others. I can trust truthful Tamara on

the topic of motorcycles, even though she is not an epistemic authority on motorcycles,

because I can rely on her not to assert things of which she is uncertain, and to admit it

when she does not know something. Having faith in a speaker does not require taking the

speaker to be an authority, but it does require taking the speaker to be truthful, even when

the speaker is an epistemic authority.

VII

We have seen that Aquinas has an appealing pluralist take on testimonial justification that

is not Defaultist, nor is it simply Inferential, nor simply Interpersonal. By including both

testimonial opinion and testimonial faith, Aquinas can say (unlike strict Interpersonalists)

that inferential belief from eavesdropping or court testimony is nevertheless testimonially

based belief, of the strong opinion kind. He can also say (unlike strict Inferentialists) that

we do sometimes get justified belief by choosing to trust a speaker, and he has some

resources for explaining how such faith is justified. Aquinas is an anti-reductionist, in the

27

sense that he would not say that all testimonial justification reduces to other kinds of

justification (such as inferential justification). But his account raises interesting

considerations, absent from current anti-reductionist discussion, about the role of

adherence to the speaker, and the role of truthfulness in supporting such adherence.