# REPLY TO COMESAÑA*

## RÉPLICA A COMESAÑA

Carl Ginet**

1. In the "Sentence-Relativity" section of his comments, Comesaña discusses my attempt (in the "Relativity to Sentences" section of my paper) to convince readers that there cannot be two different sentences that say the same thing but only one of which counts as self-evident according to my definition (D1-prelim). In his discussion of this in his comments at the Lehrer conference<fnref n="1" />, he suggested (as he reports here) that there is a less involved (and more demonstrative) argument to the desired conclusion, namely, the following argument (as he puts it here):

> "if p satisfies the definiens of [(D1-prelim)], that means that every subject that fully understands p believes what p says, and if q says the same thing as p, then every subject who fully understands q also believes what q says, for he believes what p says, and q says the very same thing. It is impossible, then, for two sentences to be such that they say the same thing and yet only one of them satisfies the definiens of (D1) – impossible as a matter of logic, regardless of what we mean by 'full understanding' and 'what a sentence says'."<fnref n="2" />

It seemed to me that this argument somehow fails to address what was really worrying me about the relativity to sentences of my (preliminary) definition of self-evidence. This led me in footnote 3 of the new version of my paper to formulate and rebut what I thought was essentially the same argument as the one Comesaña suggests. I now

<table><tr><td>Veritas</td><td>Porto Alegre</td><td>v. 55</td><td>n. 2</td><td>maio/ago. 2010</td><td>p. 24-32</td></tr></table>

<footnote>* See Juan Comesaña, Comments on Carl Ginet's "Self-Evidence", in: *Veritas*, 54, 2 (2010), p. 41-47.</footnote>

<footnote>** PhD. in Philosophy. Professor of Philosophy at the Cornell University.</footnote>

<footnote n="1">¹ Conference on the Epistemology of Keith Lehrer, PUCRS, Porto Alegre (Brazil), June 27-29.</footnote>

<footnote n="2">² See Juan Comesaña, Comments on Carl Ginet's "Self-Evidence", op. cit., p. 42.</footnote>
see (what, I'm embarrassed to confess, should not have been hard to
see) that I was wrong in this last thought. The defective argument I
consider in footnote 3 is not the same as Comesaña's argument and in
fact there is nothing wrong with Comesaña's argument. That argument
turns solely on the assumption that if two sentences say the same thing
then to *believe* what one of them says is to believe what the other says,
an assumption I granted when stating the problem (and the argument
does not turn, as my footnote 3 suggests, on the false assumption that
if two sentences say the same thing then to *understand* what one of
them says is to understand what the other says). It is clear, I now agree,
that Comesaña's argument does demonstrate that there cannot be two
sentences that say the same thing but only one of them satisfies the
definiens of my (D1-prelim).

But, having seen this, I still find myself with the suspicion that there
is a problem with the relativity to sentences of my way of defining self-
evidence that is unaddressed by Comesaña's argument. I now think
I see where my worry really comes from. I have been reading into my
definition something that is not explicitly there (and not implicitly there
either, in any strict sense); and this merely understood bit does belong
to the definition I really wanted to offer: I failed to adequately articulate
my real thought. In the following revision of (D1-prelim) the previously
merely understood part is in italics:

(D1-prelim*) For any declarative sentence **p** whose meaning is such
that what the sentence **p** says does not vary from one
context of utterance to another, it is self-evident that **p** if
and only if: the sentence **p** is such that, for any person S,
if S understands what the sentence **p** says then it follows
that S believes what **p** says, *expressed that way*.

By 'S believes what **p** says, *expressed that way*' I mean something
for the truth of which it is necessary that either S believes that what **p**
says is true, or in suitable circumstances S would sincerely assert the
sentence **p** or would sincerely assent to another's assertive use of that
sentence.

The problem I was worried about does arise for (D1-prelim*). It does
need to be the case that it is not possible for **p** and **q** to say the same thing
and yet **p** satisfies (D1-prelim*) and **q** does not. If this were possible then
what **p** says would be self-evident and what **q** says would not be self-
evident, even though what **p** says is identical with what **q** says. But the
sort of argument Comesaña suggests can't show this to be impossible.
This is because 'S believes what **p** says, *expressed that way*' (unlike 'S
believes what **p** says') **is** an intensional context (as is 'S believes that what **p** says is true'). So, even if 'what **p** says' and 'what **q** says' refer to the same thing, 'S believes what **p** says, expressed that way' does not entail 'S believes what **q** says, expressed that way'. S may believe what **p** says, expressed that way, but fail to believe what **q** says, expressed *that* way, because she fails to understand what **q** says. So a different sort of argument is needed. The sort I gave in my section "Relativity to Sentences" will fill the bill, I think, as well for (D1-prelim*) as it does for (D1-prelim).

2. In my footnote 3 I claim that 'S understands what **p** says' entails 'S knows some truth of the form "What **p** says is that r".' Comesaña finds two problems with this claim.

2.1 First, he thinks it is false. He says:

> "it seems to me that, as we ordinarily use the term 'understand,' to know a truth of the form 'What p says is that r' may be needed in order to understand the sentence p, but surely not in order to understand what p says. Thus, a monolingual Japanese speaker understands what the sentence **snow is white** says, although he doesn't understand the sentence snow is white."<fnref n="3" />

It seems to me that Comesaña is just wrong here about how we ordinarily use the term "understand" in English. A monolingual speaker of Japanese does **not** understand what the sentence 'snow is white' says, or what any English sentence says. Suppose that S is a monolingual Japanese speaker who believes that snow is white; and suppose that S is looking at a sheet on which is written the English sentence "Snow is white" and is looking puzzled. If I point to the sentence and say, "He does not understand what that sentence says", I surely speak the truth. My claim does not invoke a special technical sense of "understand" but is in accord with the ordinary use of the word. And if I go on to say, "but he *believes* what that sentence says". I also speak the truth. So, although 'S believes what **p** says' does **not** entail 'S knows some truth of the form "**p** says that r"', 'S understands what **p** says' does entail this. 'S understands what **p** says' provides an intensional context for 'what **p** says', but 'S believes what **p** says' does not. Why is there that difference between 'understand' and 'believe'? It's hard to say. But it is the way those words are used.

<footnote n="3">³ Id. ibid., p. 42.</footnote>
2.2 Comesaña's second problem with my claim that 'S understands what p says' entails 'S knows some truth of the form "What p says is that r"' is that "if self-evidence is... understood in terms of knowing truths regarding what sentences say, then we are explaining this kind of a priori knowledge in terms of a posteriori knowledge." It is true that, on my account, S's being justified by self-evidence in believing that p requires S to know, with respect to some sentence that says that p, what that sentence says, and that knowledge is indeed a posteriori. I affirm (in my section "Self-Evidence is Non-Inferential A Priori Justification") that if it is self-evident to S that p then the fact that constitutes S's being justified in believing that p is simply the fact that she fully understands, i.e., knows, what p (or some other sentence that says that p) says. But, as I assert there,

"this sort of justification is clearly a priori (if any is). It certainly satisfies any plausible negative constraint on a priori justification: it is not justification by sense perception or by introspection; nor is it by inference ultimately from perceptual or introspective beliefs. Indeed, the only experience [or a posteriori knowledge] that justification by self-evidence requires of its subject is whatever was needed in order to fully understand what the sentence in question says, and that is no reason to deny that the justification is a priori."<fnref n="4" />

I say a bit more about this in my reply to Hetherington.

3. According to Comesaña, in the argument of my "Relativity to Sentences" section I commit myself to the claim that "if two sentences (A) and (B) are such that it is possible for anyone to fully understand them and yet adopt different doxastic attitudes towards them then they do not say the same thing." It is not clear here what Comesaña means by "doxastic attitudes towards" sentences. Presumably to *believe a sentence* p is more than merely to believe that p. Perhaps it is to believe that p, expressed *that way*. So understood, he is right: I did commit myself to that claim. He offers two putative counterexamples to this claim.

The first is the pair of sentences '1+1=2' in decimal notation and '1+1=10' in binary notation; the first says (in English) that one one plus one one equals one two and the second says that one one plus one one equals one two plus zero ones. He remarks that "insofar as it seems plausible to consider someone (however irrational) who fully understands both sentences and yet believes only one of them, we are

<footnote n="4">⁴ See Carl Ginet, Self-Evidence, in: *Veritas*, 54, 2 (2010), p. 20.</footnote>
forced to conclude that they say different things", and I take it that he finds
this conclusion unacceptable. But I do not: it seems to me that they do
say different things. But it also seems to me that what each of them
says is self-evident (in the sense of (D1-prelim) and (D1-prelim*)), so
that it would not be possible to fully understand both but believe only
one.

Comesaña's other putative counterexample – the pair of sentences
"London is pretty" and "Londres est jolie – really is a counterexample.
Those two sentences do say the same thing and yet, as Kripke's example
of Pierre makes clear, it is possible to fully understand both but believe
one of them and not the other, because one does not know that they
say the same thing, because one does not know that "London" and
"Londre" name the same city. As I've said, I did suggest the claim that
this last example counters, but on reflection it seems to me that I need
have committed myself only to the more restricted claim that if **p** and **q**
say the same thing *and what they say is self-evident* (in my sense), then
no one could fully understand both **p** and **q** but believe only what **p** says
(expressed that way) and not what **q** says (expressed that way). And
this claim still seems to me to be true. It is true even for cases satisfying
this description where S does not know that **p** and **q** say the same thing,
e.g., where **p** is "If London is pretty then London is pretty" and **q** is "Se
Londres est jolie alors Londres est jolie".

But in the same section I hazard another claim on this subject that
reflection on the Kripke example shows me I should take back. I say, "In
general, if two sentences do say the same thing, then anyone who fully
understands both sentences must see that they say the same thing."
This claim can also be shown false by sentences that use directly
referring terms, like proper names or demonstratives. Consider the pair of
sentences mentioned at the end of the last paragraph: "If London is pretty
then London is pretty" and "Se Londres est jolie alors Londres est jolie".
These say the same thing, a thing that is self-evident by my definition.
Yet someone who mistakenly thinks that "London" and "Londres" name
different cities will mistakenly think that those sentences say different
things; and yet such a person might know what city "London" names and
also what city "Londres" names, by, e.g., having been directly acquainted
with the city under that name. Will restricting the generalization by
making exceptions of sentences that contain such directly referring
terms – saying that if two sentences say the same thing then anyone
who fully understands both sentences must see that they say the same
thing, *unless* the sentences contain different directly referring terms that
have the same referent – make it true? I think so but I cannot explore
that question here.
4. At the end of his "Sentence Relativity" section Comesaña says that, according to me, "you don't fully understand a sentence S unless you can recognize which of all the other sentences that you fully understand say the same thing as S. I wonder whether, according to Ginet, anyone ever fully understands a sentence." He thinks that I've placed so heavy a demand on fully understanding a sentence that no one ever meets it. Presumably he would want to suggest the same about the more restricted generalization I propose at the end of the last paragraph. But I don't see why he thinks this. The generalization requires only that anyone who fully understands a sentence (which satisfies the restriction), *should he consider* together that sentence and another sentence he fully understands (which satisfies the restriction) and the question whether they say the same thing, must judge that they do. It does not require that he must actually have done this for every pair of sentences belonging to a certain set of sentences before it can be said that he fully understands them all.

5. Comesaña finds problems with my explicit account of full understanding, specifically with my account of application competence for descriptive terms. I said that one has application competence for a term **x** if one is able to tell with respect to any candidate case, given enough relevant information about it, whether or not **x** applies to the case. Comesaña rightly notes that we must be careful what we allow in the relevant information the subject considers. It must not, for example, include the information that **x** does (or does not) apply to the case along with information as to just what it is about the case that makes **x** apply (or not apply). But Comesaña says that it also must not "include information that entails that the candidate case is an **x** or not." I am puzzled that he should say this, for it can't be right. If a subject is to be able to demonstrate competence in applying the term, she must be allowed enough information about the case to determine whether the term applies and that is information sufficient to entail either that it does apply or that it doesn't apply. Take the term "rhombus", which applies to a plane figure just in case it has four equal sides and its opposite sides are parallel. Unless I am told, or allowed to observe, all those facts about a figure, I won't be able to tell whether it's a rhombus, no matter how well I understand the term, how competent I am in applying it.

Comesaña severely doubts that this account of application competence can work for natural-kind terms like "water" or "tree" or for terms that admit of borderline cases like "table". And of course he is right. I acknowledge (in the last paragraph of my "Full Understanding" section) that the above account is not adequate for natural-kind terms, vague
terms (or, I would add, any sort of term that admits of indeterminate
cases), evaluative or essentially contestable terms, proper names (or, I
would add, demonstratives or directly referential terms generally), and
that for terms of these sorts (and no doubt others) it will be necessary to
complicate in one way or another the account of application competence.
I do not try to suggest how any of those complications should go; but
of course a constraint on correct accounts of them is that they largely
conform with our intuitions as to what should and should not count as
cases of competence with a term (and that they not yield the dire result
that hardly anyone has application competence for such terms or fully
understands sentences containing them). Application competence for the
natural-kind term “water”, for example, should not require knowing such
a posteriori necessary truths as that water is H₂O, but it should require
knowing that whether “water” applies to something is not determined
merely by its superficial appearance but also by its underlying nature.
Someone who does not know this, who would be baffled at the suggestion
that something superficially resembling water in all respects but having
a radically different underlying nature is not water, does not understand
the term “water” in the way we do. And application competence for a
term admitting of indeterminate cases should, of course, not require the
subject to know with respect to such cases (e.g., the case Comesano
describes) whether or not the term applies, but rather to know that they
are cases where the term does not clearly apply or not apply (and to
know of clear cases that they are ones where the term clearly does or
does not apply).

I did suggest that the account of application competence I gave
(requiring the ability to tell with respect to any candidate case, given
sufficient information about it, whether the term applies or not) is apt for
many terms in mathematics (such as the terms “triangle”, “rhombus”,
“right angle”, “Euclidean plane figure”, “three”, which appear in some
of my sample sentences). Comesaña seems to doubt this and offers two
reasons for his skepticism. The first he expresses this way:

"Take, for instance, two. In order to have application-competence with respect to two, do I have to know, of any candidate case, whether it is the number two or not? How would I go about doing that? (Do I have to solve one of the most difficult philosophical problems in order to have application-competence with respect to two?) Or do I have to know, of every candidate number of objects, whether they are two or not? In that case, the vagueness in the terms for the objects will infect two itself with vagueness."<fnref n="5" />

<footnote n="5">⁵ See Juan Comesaña, Comments on Carl Ginet's "Self-Evidence", op. cit., p. 46.</footnote>
I think the second is the only plausible alternative here. And I don't
see that it would mean that the vagueness in terms for objects would
infect “two” itself with vagueness. The requirement with respect to a
numeral n (for an integer) would be the ability to determine with respect
to a candidate set of Fs, each of which is determinately an F, whether the
number of Fs in the set is n (or for a very large number of Fs, to know how
in principle to go about determining whether the number is n).

Comesaña's second reason for skepticism comes out in the following
remarks:

"It still seems to me that many of the reasons why we favor a "more complicated" account of the notion of full understanding [and application competence] ... for the case of, e.g., natural kind terms will apply also to mathematics and logic. For instance, if one is impressed by Putnam's arguments regarding the linguistic division of labor, then surely that division of labor takes place as much (or more) in logic and mathematics as it does in botanic [sic]."<fnref n="6" />

It's true that linguistic division of labor takes place in mathematics
as well as in botany, but I don't see why we should take that as a reason
for supposing that my uncomplicated requirement for application-
competence won't work for mathematical terms that are subject to such
division of labor. Putnam's point, I thought, was that in fact many us
do *not* have application competence for terms like "beech" and "elm"
and a great many other kind terms in the natural sciences, do not fully
understand those terms; only certain experts do. And, of course, the same
holds for many kind terms in mathematics. Many mathematicians fully
understand what "regular topological space" means, but I (along with
most non-mathematicians) don't. There are therefore some self-evident
propositions about regular topological spaces that are self-evident *to*
those mathematicians but not to me. But there seems to me nothing
surprising in that.

In the last section of his comments Comesaña expresses strong doubt
that there are any sentences such that what they say is self-evident in
my sense, such that fully understanding what they say entails believing
it. He thinks that there could, for instance, be a case of someone who
fully understands what "one plus one is two" says but does not believe
it. To produce a good reason for thinking that there can be such a case
would, I think, to provide a description of one that makes it clear how
it could be. I don't think Comesaña has done that. He tells us that there
could be someone who, while fully understanding what that sentence

<footnote n="6">⁶ Id. ibid.</footnote>
says, does not believe it because he is irrational, or because he lacks the
motivation or the capacity to believe it. But this seems simply to beg the
question against the view that believing what that sentence says is (part
of) what constitutes understanding it: one has to already assume that
this view is false in order to suppose that fully understanding it leaves it
still undetermined whether the subject believes it or not, leaves it open
whether the subject has the "motivation" or rationality to believe it or
the capacity to have the attitude of belief towards it.

He tells us that Hartry Field actually does fail to believe what the
sentence "one plus one is two" says while fully understanding it. Being
ill-acquainted with the details of Field's views about the semantics of
arithmetic, I am ill-equipped to say anything on the question whether
Field's views really commit him to disagreeing with us ordinary folk who
in ordinary life go about affirming (what we take to be) arithmetic truths.
But I would be astonished if Field did not occasionally manifest sincere
belief in various arithmetic truths – for example, when adding up the
restaurant tab or filling out his income tax forms – or, if he were asked to
correct arithmetic tests of first-graders, he would summarily declare all
of their answers wrong. It is the belief that one plus one is two (or that
one plus one is *not* four) that any of us would manifest in such contexts
that I am saying is part of what constitutes our understanding what the
sentence "one plus one is two" says.