A Theory of
Propositions
(Draft)
I. Introduction
“In what is the
agreement of the thing [fact] and the statement [proposition] supposed to
consist, given that they present themselves to us in such manifestly different
ways?” (Heidegger 1967, p. 180)
In
this chapter, I will offer a theory of the nature of correspondence. Included
here is a theory of propositions
and of the correspondence relation.
II.
Propositions and Things Proposed
Recall from Chapter 1 that by
‘proposition’, I mean the primary bearers of truth and falsity. I would like to
point out a connection between propositions and things that people propose. I take it that at least some
things people propose are true; some are false. Therefore, I take it that at
least some things people propose are propositions. I might even go so far as to
say that propositions just are things
that can be proposed. (I will not go that far, however: first, because I do not
wish to be bothered by question of whether some propositions might be too
complicated for anyone to possibly propose; second, because there is no need.)
I point out a
connection between propositions and things proposed in order to draw a
distinction between thinking of propositions as the things that are proposed,
on the one hand, and thinking of propositions as proposed things, on the other. A thing is only called a ‘proposed
thing’ if it has in fact been proposed. By contrast, the thing that has been proposed need not have been proposed. It could
easily have never been proposed at all. To be clear, I am not suggesting that proposed things form a distinct
ontological category from things that are
proposed. On the contrary, I would say that proposed things are the things that are proposed; it’s
just that we call a thing ‘a proposed thing’ only once it has actually been proposed. I draw this distinction so that
no one will be tempted to think that propositions must be mind-dependent solely
because she thinks propositions are proposed
things. It should be an open question at the outset whether a thing that is
proposed may exist independently of its being proposed.
Now someone may wish to
reserve the term ‘proposition’ to refer only to those things that have actually
been proposed (or to the kind, having
been proposed). I have no problem with that usage of the term. I only wish
to make it clear that I am using ‘proposition’ differently than that. I use it
to refer to the sort of things that can be proposed—things that are true or
false.[1]
II. Propositions are
not Concrete
Some philosophers (Tarski 1944[2],
Higginbotham 1991, Armstrong 1997[3],
to name a few) believe that propositions are concrete things, such as sentences or brain states, or sums (or
classes) of sentences or brains states. I will offer three reasons why I think
this view is mistaken.
II.i.
Reason One
Let Concrete
name the thesis that every proposition is a concrete object located somewhere
in space or space-time or is dependent upon an object or objects located in space
or space-time.[4]
The first step in the argument is to observe that Concrete is not a contingent thesis. That is, advocates of Concrete should (and most likely do)
think that propositions must be
concrete. (How, for example, could a sentence or brain state ever be abstract?) In other words, if Concrete is true at all, it should be
necessarily true. Here is further support: given the modal axiom S5, if it is
even possible for there to be necessarily existing abstract
propositions, then there really are such things. Therefore, if Concrete is true at all, it better be necessarily
true to rule out the possibility of necessarily existing abstract propositions.
The next thing to
notice is that if Concrete is true,
then it exists. (We may view this inference as an instance of
‘adjective-dropping’ in first-order logic: e.g. $x
(xF & xG) → $x
(xG),
where F = ‘true’ and G = ‘identical to the proposition Concrete’.[5])
Notice also that the inference from being true to existing is probably not a contingent
matter; it is plausibly a necessary truth. That is, it is plausible that it is necessary
that if Concrete is true, then it
exists. This is plausible given that it is plausible that there cannot be
something that does not exist—and if there cannot be something that does not
exist, then there cannot be a true proposition that does not exist. (A
Meinongian may deny this step, but it is unlikely that a believer in concrete propositions would.[6])
What follows is that if Concrete
is necessarily true, then Concrete necessarily exists.
The trouble is that
there do not seem to be any necessarily existing concrete particulars with
which to identify Concrete. Sentences on paper can be erased or
destroyed by fire. Brain states can
be damaged by oxygen deprivation. Mereological sums (or classes) of brains states or of sentences can dwindle
away, though the process may take awhile. Perhaps science will reveal that
there are fundamental spatial things—superstrings, say—that cannot cease to
exist. But surely Concrete is not
a superstring. So what could Concrete
be?
Perhaps Concrete, along with every proposition,
is part of a special class of particulars that are not reducible to anything
investigated by empirical science. They are concrete
alright, but they escape empirical detection: no one could say, “Look! That
scratch is the impact of a proposition.” The trouble with this view, apart from
sounding incredible, is that if it were true, then we would have had no way to
come to believe that there are any propositions in the first place. If Concrete is floating in space—somewhere
near the peaks of Mount Kilimanjaro, say—and is completely undetectable, how
should we have ever come to grasp it? It seems that we would not have. Yet,
clearly we have.
The reductio argument against Concrete, then, can be expressed as
follows:
(1) Assume
Concrete is true.
(2) If
Concrete is true, then it is
necessary that Concrete is true.
(3) Therefore,
it is necessary that Concrete is
true.
(4) Necessarily,
whatever is true exists.
(5) Therefore,
it is necessary that Concrete
exists.
(6)
No
sentence or brain state (or sum of them) necessarily exists.
(7) Therefore,
Concrete is not a sentence or a
brain state (or sum of them).
(8)
More
generally, the types of concrete things whose existence might be conceived to
be necessary are not themselves propositions (as no such thing exhibits any
proposition-like properties).
(9) Therefore,
Concrete is not concrete, which is
a contradiction.
I take the reductio argument against Concrete
to be fairly strong as far as philosophical arguments go. The three best ways
out that I have been able to think of have serious costs, as I will argue next.
Objection
1:
Concrete is necessarily true, but only if it exists.
Perhaps we can understand ‘necessary
proposition’ as a proposition that is essentially
true: it is true when and only when
it exists. (A contingent proposition, by contrast, is true in some, but not all, situations in which
it exists.) If we say this, we may then say that Concrete, though necessarily true, can fail to be true by failing
to exist. Therefore, there is no need to affirm (2).
Unfortunately, this
move has a cost. As Alvin Plantinga (2006) has noted, if necessary propositions
are the same as essentially true
ones, then there seems to be too many
necessary propositions. Consider, for example, <there are brains>. That
proposition does not seem necessary. Yet, if propositions are things that
depend upon brain states (say), then clearly <there are brains> cannot
exist unless it is true. In other words, <there are brains> would be essentially true, which means that it
would be necessarily true. The result is the same if propositions depend
instead upon sentences: <there are sentences> would be essentially true
and so necessary. What we have here is the dubious consequence that the
existence of brains or sentences (or whatever other spatial things propositions
might depend on) is broadly logically necessary—no less necessary than the
proposition than every square has four sides. Surely, that’s not correct.
Objection
2:
It is not necessary that whatever is
true exists.
Perhaps we can deny (4) by supposing
that it is possible for Concrete to be true even if Concrete does not exist. However, if we
say that, then we will have to give up serious
actualism—the view that it is impossible for something to have a feature,
or be predicable, unless it exists. Only then can we say that Concrete can be true even at times or in situations in which it does not exist. The
problem is that no advocate of Concrete
should be willing to give up serious actualism: no advocate of Concrete should be willing to say that
there can be things, such as Concrete, that do not exist. A believer
in Concrete who believed that would be committed to saying that
during the times when Concrete
does not exist, Concrete is still
a concrete particular. In other words, she would be committed to saying that
there can be concrete particulars
that do not exist. No one should be willing to say that, it seems to me.
Objection
3:
Concrete can be true at a world without being true in it.
Kit Fine (1985) introduces a distinction
between ‘inner truth’ and ‘outer truth’. A proposition has inner truth relative to a world only if it exists in that world; it
has outer truth relative to a world whether or not it exists in that world. An
outer truth is supposed to be a truth that correctly describes a world without
necessarily being in that world. It is true at
that world, but not necessarily in
it. (Thus, every proposition that is true in a world is true at that world, but
not every proposition that is true at a world is true in it.) Using this
distinction, perhaps we can say that Concrete
is necessary in the sense that Concrete
correctly describes every world, even though it is not in all of them. Concrete,
like every necessary truth, is outwardly true relative to every world and every
time, though Concrete only exists
in a few worlds at a few times (see Iacona 2003).
I see two problems with
this way out. One problem is that I know no plausible way to define ‘inner
truth’ and ‘outer truth’. My best guess would be that ‘a proposition P is true
relative to a world W’ means the same as ‘if W were actual, then P would be
true’; and ‘P exists in a world W’ means the same as ‘if W were actual, then P
would exist’. That would be my best
guess if it did not imply that every outer truth just is an inner truth. But unfortunately, it does imply that every outer truth is an inner truth, if we assume
that there cannot be things that do not exist (which was Objection 2).
To see why every outer
truth is an inner truth given the above definitions, suppose P has outer truth
relative to W. Then, if W were actual, P would be true. But if P were true,
then P would exist, assuming that P cannot be anything, not even true, without
existing. That means that if W were actual, then P would exist, which is what I
would have guessed was meant by ‘P exists in W’. Thus, if P has outer truth
relative to W, then it also has inner truth relative to W. This is so for any
P. However, since it is clear that not
every outer truth is supposed to be an inner truth, my best guess as to the
meaning of these notions must be mistaken.
We may, therefore, try
to work with a loose and vague understanding of the distinction between inner
and outer truth. However, even the vaguest (or minimal) understanding leads to
trouble—trouble that appears to have gone unnoticed in discussions of inner and
outer truth. The trouble consists in there being fewer necessary truths than there seem to be. For example, if Spatial is necessary, then it seems that
<Concrete is necessary> is
also necessary. (This is an instance of S4.) But if we wish to make use of
inner and outer truth, then we cannot say that < Concrete is necessary> is necessary without getting
entangled in a contradiction. I’ll explain. Let Chaos
be a distant future time after which brains and sentences (and anything else
propositions might be) have long since been effaced from our universe. We can
correctly describe Chaos as a time
when there are no propositions, no truths, and no Concrete. Even on the vaguest (minimal) understanding of
outer truth, it should be safe to say that a proposition that correctly
describes a world or situation is outwardly true relative to that world or
situation. Thus, it should be safe to say that <there are no truths> is
outwardly true at Chaos given that
it correctly describes Chaos. But
recall our hypothesis: necessary truths have outer-truth at every world and
time, including Chaos. It follows,
then, that both <Concrete is
necessary> and <there are no
truths> are true (outwardly) at Chaos.
A contradiction is now a step away. If <Concrete is necessary> is true at a situation, then so is
<Concrete is true>. That
means <Concrete is true> is
true at Chaos, which in turn means
that <there is a truth>
is true at Chaos. Thus, both <there is a truth> and <there are no truths> are true at Chaos. That appears to be a
contradiction. To avoid this contradiction, then, an advocate of the third
objection is committed to saying that although Concrete is necessary, <Concrete is necessary> is not. But
that is implausible.
II.ii.
Reason Two
Consider, <some volcanoes
erupted>. Intuitively, that proposition entails that there are volcanoes but
does not entail that there are
people. That is, if that proposition were true, then it is guaranteed that
there are volcanoes, but it is not guaranteed that there are people. Yet, if
there were no people, then there would be no sentences or brain states, or
anything else that a concrete
proposition might be identified with. In other words, if there were no people,
then there would be no true propositions. Thus, <some volcanoes erupted>
would not be a true proposition. Hence, if <some volcanoes erupted> were true, then there really would be people—the existence of people
would be guaranteed. But that is not plausible; therefore, it is not plausible
that <some volcanoes erupted> is a concrete thing.
How
might someone reply? The best reply I have seen is to say that <some
volcanoes erupted> does not entail that there are people because it describes situations or worlds in which
people do not exist, despite the fact that the proposition itself would not
exist were there no people. This reply makes use of the distinction between
inner and outer truth: that is, <some volcanoes erupted> has outer truth
but not inner truth relative to situations in which people do not exist.
I
have already said why I do not think a distinction between inner and outer
truth will help. I said that the distinction, if intelligible at all, has the
counter-intuitive implication that a proposition P can be necessary even if
<P is necessary> is not. Here, I will express an additional concern. The
concern has to do with what it might mean to say that a proposition describes, or is true relative to a situation or world. The
relation of describing sounds like
the relation of corresponding to. In
this case, however, the object being described is not a fact; rather, it is a situation or world. I ask, “What is a
situation or world?” And, “What is it to accurately describe a situation or a
world?” If someone asked me those
questions, I would answer thus:
A situation is
an abstract state of affairs (or proposition). A world is a big (maximally big)
state of affairs. A proposition accurately describes
a situation by being entailed by it, that is, by being such that were the
situation actual, the proposition in question would be true. Perhaps also,
there is an important sense in which a situation mereologically includes
any propositions that describe it.
Of course, that sort of answer is
of-limits to the advocate of concrete propositions: first, because she will
surely not include proposition-like abstract
states of affairs in her ontology, and second, because she cannot allow there
to be a situation (for example, one in which there are volcanoes but no people)
that implies both the truth of a
proposition and the non-existence of
all propositions. But then, what answer can she give? What concrete things are situations or worlds, and how do propositions
manage to describe such things?
David
Lewis has an answer to the first question: worlds are causally isolated
spatial-temporal universes, and situations (or “Lewis-propositions”) are sets
of worlds. If an advocate of concrete propositions accepts the existence of
Lewis worlds (though I suspect few do), she can say that concrete propositions
describe concrete worlds or sets of concrete worlds.
Still, how do propositions manage to describe
Lewis-worlds? We might attempt an answer in terms of intentional properties of
sentences or brain states. However, it is difficult to see how intentional
properties could grab on, so to
speak, a particular world out of the sea of infinitely many similar worlds that
neighbor it. We cannot say, for example, that an intentional property grabs
onto a world by virtue of a certain causal
connection between a world and a sentence (say), for worlds are causally
isolated by definition. Someone might instead suggest that propositions
describe worlds by virtue of corresponding
to them (in the way that true propositions correspond facts), but then
there is the equally difficult problem of seeing how concrete propositions
should correspond to Lewis-worlds. I
will offer an analysis of correspondence according to which propositions may,
in principle, correspond to Lewis-worlds, but as we will see, my analysis
entails that propositions are not concrete. It seems to me, then, that the
prospects for finding an account of how concrete propositions might describe
worlds or situations are grim. At any rate, advocates of concrete propositions
who wish to employ the distinction between inner and outer truth have some
explaining to do.
II.iii.
Reason Three
Let P be a proposition whose existence
is not necessary. Ask: if P were to have not
existed, would it still have been possible
for P to exist? It may seem so. Consider that P’s existence is possible right
now (given that P actually exists right). How could that change? How could
there be a situation (or world) in which it is not even possible for P to exist?
It may seem that there could not be one. That is, it may seem that the
possibility of P is itself necessary. (This is an instance of S5.) Suppose that
is so. Now consider that if <P exists> is possible, then <P exists>
exists (given serious actualism[7]).
And if <P exists> exists, then P exists, too. Therefore, by the
contraposition, if P does not exist,
then <P exists> is not
possible. But that contradicts the intuition expressed above: that is, if P
were not to exist, it would have still been possible for P to exist. To avoid
this contradiction, I suggest that we reject the starting assumption that there
is a proposition whose existence is not necessary. Yet, if propositions exist
necessarily, then they are most likely not concrete. Therefore, propositions
are most likely not concrete.
This
argument just given assumes that if something is possible, then it is
necessarily possible. That is, being
possible entails being necessarily
possible. (Here is more technical way of putting the assumption: the accessibility
relation between possibilities [propositions that are possible] is symmetric.)
I suspect that many philosophers would (and do) find that plausible, but others
may demur. This third reason against concrete propositions, then, should appeal
to those who accept that being possible
entails being necessarily possible.
III.
Propositions as Arrangements
If propositions are not concrete, what
kinds of things are they? Here is a hypothesis:
(10)
Necessarily, for all x (if x is proposition, then x is an
arrangement of properties that are individual essences),
where
(11)
‘x is an individual essence’ =def ‘Possibly, there is a y (y
exemplifies x, necessarily (if y exists, then y exemplifies x, and necessarily,
for all z (if z exemplifies x, then z = y))’.[8]
According to this hypothesis,
propositions are themselves arrangements of properties—specifically, of
individual essences. It might also be that every arrangement of individual
essences form a proposition (then we could analyze
propositions as arrangements of individual essences), though the hypothesis
under discussion here leaves that open.
To better understand
the hypothesis, let us consider an example: <Tibbles is on the mat>. That
proposition, according to the hypothesis, is an arrangement of individual
essences. Which ones? These, perhaps: being
Tibbles and being the mat. (I
have not said anything precise about what being
Tibbles or being the mat are. One
might wonder, for example, if being
Tibbles is the property of being the
thing named by ‘Tibbles’, or if it is the property of being the one cat I got from my Grandma, or something else. Perhaps
the answer depends upon what proposition
‘Tibbles is on the mat’ is supposed to express. Nothing I say here turns on how
these details are specified.) Thus, <Tibbles is on the mat> is an
arrangement of the properties, being
Tibbles and being the mat.
The arrangement
consists of being Tibbles standing in
a certain relation R to being the mat.
Which relation is R? Here is an answer: R is the relation that being Tibbles bears to being the mat, such that anyone who
fully grasps R grasps the relation of sitting
on. Or if you do not like that answer, here is another: R is the relation r,
such that necessarily, if an x bears the sitting on relation to a y, then every haecceity of x
bears r to every haecceity of y. On either answer, we might say
that the relation of sitting on is a constituent of <Tibbles is on the mat> (for a definition of ‘constituent’,
see Chapter 2, section VI).
One virtue of treating
propositions as arrangements of individual essences is that it allows us to
understand propositions in terms of the familiar category, Whole (thing with
parts): a proposition is a whole that has individual essences as parts and that
exists if and only if its parts are related in a certain specified way.
One interesting
implication of treating propositions as arrangement of essences is that
propositions themselves may be
objects of correspondence for “high-order” propositions. For example, if
<Tibbles is on the mat> is an arrangement consisting of being tibbles and being the mat, then there may be a proposition that corresponds to
that arrangement. For example: <being
tibbles bears R to being the mat>,
where ‘R’ is the relation r, such that necessarily, if an x bears
the sitting on relation to a y,
then every haecceity of x bears r to every haecceity of y.
This implication may help us appreciate why there are propositions in the first
place. There are propositions because there are arrangements whose parts have
individual essences, and propositions just are arrangement of those essences.
I’d like to now
consider a couple worries that one might have concerning the hypothesis, (10).
First, there are many types of propositions (negative, counterfactual, tensed,
and so on), and we might wonder whether (10) can hold for every type of
proposition under the sun. I will address this worry in Chapter 4 by showing
how (10) may hold for the most challenging test-cases.
A second worry is that
(10) makes use of individual essences. Some philosophers are skeptical that
there are such properties (see Menzel 2008). They are skeptical in part because
it is difficult to see how individual essences might be analyzed—either in
terms of more familiar, qualitative properties, or in terms of their
exemplifiers, and in part because their inclusion into one’s ontology adds
unwanted metaphysical complexity. My purpose here is not to defend the
existence of individual essences against objections (if a defense is possible,
it would surely require a fully essay in itself). Instead, I will offer a brief
reason to think that individual essences are no more (or less) problematic than
singular propositions—propositions
that ascribe a feature to a particular individual. Individual essences are no
more (or less) problematic because they may
be analyzed as a type of singular proposition. Here’s how:
(12) 'x
is an individual essence' =def 'there is a o
(x is a
singular proposition about o, and x is true if and only if o
exists’.
I am assuming
that we understand at an intuitive level what it means for a proposition to be
about something. Suppose that is so, and suppose that we have no objection to
the existence of singular propositions about things. Then I do not see why we
would object to the existence of those singular propositions called ‘individual
essences’—for example, propositions that report the existence of a particular
thing. We can say that these propositions/individual essences are “exemplified”
just by being true. (It may have been noticed that if individual
essences are singular
propositions, then there is no hope of analyzing
propositions as arrangements individual essences without circularity. However, there is still the
option of analyzing propositions that are
not individual
essences as arrangements of
propositions that are individual
essences.) I conclude here that
although the existence of individual essences is a potential
cost of our theory of propositions, it is only actually a cost if the existence of singular propositions is a
cost, too.
IV.
About Aboutness
If propositions are arrangements of
individual essences, then we can explain what it is for a proposition to be about something: we can say that a
proposition is about a thing by
virtue of containing a part that would be exemplified by that thing if it
existed. To be more precise, we can say the following:
(13)
‘x is about y’ =def ‘there
is a p (p is a part of x, p is an individual essence, and
necessarily, (if p is exemplified, then y exemplifies p)’.
(13) analyzes aboutness in terms of
individual essences. This leads to circularity we analyze individual essences
in terms of singular propositions about
things. But we certainly do not have
to analyze individual essences as singular propositions: recall (11). The
reason I offered an analysis of individual essences as singular propositions
was to show that including individual essences in our ontology is no more
problematic than including singular propositions in our ontology: both are
equally suited to be the building blocks for propositions. However, I will
later offer a theory of the correspondence relation, and one way to test that
theory is to see whether the theory entails that true propositions correspond
to things they are about. If we hope to be precise
in our tests, it will help to go beyond an intuitive grasp of ‘aboutness’.
The purpose of this section, then, is to offer a reasonable account of
aboutness so that we can later test more precisely whether true propositions
correspond to things they are about. This account of aboutness is not essential to our metaphysical account of
propositions and correspondence, however.
Think again about (13).
Notice that (13) does not entail that
when a proposition is about something, there is a thing that the proposition is about. When I say, for example,
that a proposition is about Socrates, according to (13), what I am saying is
that the proposition contains one of Socrates’ individual essences. To say that does not commit me to saying that
Socrates exists. This is a favorable result because there is an intuitive sense
in which propositions can be about things that do not exist: take for example,
<Socrates died>.
It will also be useful
to talk about propositions being indirectly
about things. For example, consider <James believes <Socrates is
wise>>. That proposition is primarily about a proposition, namely, <Socrates is wise>. But there is also a
sense in which it is about Socrates. That sense might be spelled out
recursively as follows:
(14)
‘x is indirectly about y’ =def ‘
basis clause: x
is directly about y.
recursive
clause: x is directly about a proposition that is indirectly about y’,
where ‘directly about’ just means what
‘about’ means in (13). To avoid confusion, I will now revise the definition of
‘x is about y’ as follows:
(15)
‘x is about y’ =def ‘x
is directly about y, or x is indirectly about y’.
Or if you like:
(16)
‘x is about y’ =def ‘x
is directly or indirectly about y or the parts of y’.
A virtue of this analysis of aboutness
is that it seems to yield favorable results for propositions as well as for things that are not
propositions. Consider first thoughts.
Suppose that a thought is the grasping of a proposition. More precisely,
suppose a thought is an arrangement consisting of a mind bearing the grasping
relation (or some relation in the neighborhood) to a proposition. Take an
example: I have the thought that Tibbles is on the mat. We may analyze this
situation as an arrangement consisting of me bearing the grasping relation to
<Tibbles is on the mat>.[9]
Given this analysis, <Tibbles is on the mat> is part of my thought. (It
is the content of my thought, as they
say.) Since being Tibbles and being the mat are parts of <Tibbles
is on the mat>, by transitivity, they are also parts of my thought. Since
these parts are themselves individual essences of Tibbles and the mat, it
follows from our account of aboutness that my thought that Tibbles is on the
mat is about Tibbles and the mat. That’s the right result.
I
believe we can get the right result for concepts,
too. To do so, we might suppose that a concept is a grasping of (or a
disposition to grasp) an individual essence. That is, suppose that a concept is
an arrangement consisting of a mind bearing some mental relation to an
individual essence. Then, every concept has an individual essence as a part and
is thereby about whatever might
exemplify that individual essence. For example, my concept of Tibbles is about
Tibbles by virtue of containing a unique and essential description (an
individual essence) of Tibbles as a part.
Of course, one may
question whether my analysis of thoughts and concepts is correct. My point here
is that the analyses are not unreasonable, and those who accept them have
additional reason to accept our definition of ‘aboutness’.[10]
…
VI.
The Nature of Falsehood
I have explained what it is to be true if CTT [the correspondence theory
of truth] is correct, but I have said nothing about what it is to be false. It might be thought that if we
can say what it is to be true, then saying what it is to be false will be
easy—trivial even. Unfortunately, that is not so. The thought that it is easy
to define falsehood in terms of truth might come from the thought that we can
define falsehood like this:
(19) ‘x is
false’ =def ‘x is not true’.
But (19) will not do: it implies that you and me are false given that we are not true; but surely we are not false. Suppose, then, we add
the following “fix”:
(20) ‘x is false’
=def ‘x is a proposition, and x not true’.
This is better. But there are still a
couple difficulties. First, I identified propositions as the bearers of truth
and falsity. So if I define ‘false’ in terms of ‘proposition’, then that means
I have identified propositions as
things that are true or false
propositions, which is clearly an unhelpful identification. A more serious
difficulty is this: (20) does not define ‘false’ in terms of ‘true’; rather, it
defines ‘false’ in terms of ‘not true’. We may ask, “What is the relationship
between ‘true’ and ‘not true?” More generally: “What is the relationship
between ‘is F’ and ‘is not F’?” Here is a tempting answer:
(21) ‘x is not
F’ =def ‘not (x is F)’.
But that answer will only help if we
know what a sentence of the form, ‘not (A is F)’ expresses. If propositions are
themselves arrangements, then the
most natural thing to say here is this: a sentence of the form, ‘not (A is F)’
expresses <<A is F> is false>, which is an arrangement consisting
of the property being <A is F> standing
in the relation of exemplification to the property being false. In other words, (21) should be translated as
(22) ‘x is not
F’ =def ‘<x is F> is false’.
But then, (20) will be translated as:
(23) ‘x is
false’ =def ‘x is a proposition, and <x is true>
is false’.
And clearly that will not do: it is patently circular. What are we to do?
I
suggest we do the following: we interpret ‘not (A is F)’ as ‘A lacks F’. Thus,
(20) becomes:
(23)
‘x is false’ =def ‘x is a proposition, and x
lacks true’, where ‘lacks’ expresses the relation of lacking.
According to (23), a proposition is
false by bearing the lacking relation
to the property being true. The
relation of lacking is a relation a
thing bears to something just in case it does not bear the having (exemplification) relation to that something. Put another
way: for every property P and every
thing T, either T exemplifies P or T lacks P. (This is not a definition of ‘lacks’ of course: ‘lacks’
is as much a primitive here as ‘has’ or ‘exemplifies’.) On this account ‘not’
gets analyzed in terms of ‘lacks’. If treating ‘lacks’ as a primitive is a
cost, that cost is offset, I think, by the benefit of not having to treat ‘not’
as a primitive; everyone has to treat
one or the other as a primitive.
That
takes care of the difficulty of explaining the relationship between ‘true’ and
‘not true’. What about the difficulty of saying what propositions are without
circularity? To handle that difficulty, I suggest that we identify propositions
using the following definition:
(25)
‘x is a proposition’ =def ‘$y (x
entails y)’.
The idea here is that propositions are
things that entail things. In other words, the mark of a proposition is that it
stands in the relation of entailment. As I explained above, an advocate of CTT
may treat ‘entailment’ as a primitive: she may maintain that we grasp the
relation of entailment by virtue of seeing
(being aware of) propositions entailing other propositions.[11]
(This is better than treating ‘proposition’ as a primitive because (i)
‘entailment’ is already treated as a primitive in the definition of
‘correspondence’ and (ii) it is not so clear that we grasp the general type,
Proposition, just by grasping a
particular proposition: do we grasp the type, Proposition, just by grasping
<Tibbles is on the mat>?[12])
Therefore,
an advocate of CTT may define ‘false’ in terms of ‘true’. It may not be
trivial/easy to do it, but fortunately, it is not impossible.
Before
closing this section, I’d like to point out an interesting implication of our
account of falsehood. The account entails that every proposition is either true
or false. That is, it entails bivalence. Some philosophers may regard this to
be a virtue of the account, whereas others may regard it as a cost. I will not
defend bi-valence against the charge of being a cost (that would be a
dissertation in itself). I only wish to point out that bivalence may well fall
out of CTT because
(26) If CTT is true,
then truth is analyzable;
(28) If truth is
analyzable, then so is falsehood;
(29) Falsehood can only
be analyzed as a proposition that lacks truth, if it can be analyzed at all;
(30) Therefore, any
proposition that lacks truth is false;
(31) If (30), then
bivalence;
(32) Therefore,
bivalence.
WORKS
CITED
Armstrong,
D. (1997). A World of States of Affairs Cambridge
University Press.
____
(2004). Truth and Truthmakers
Cambridge University Press.
Fine,
K. (1985). “Plantinga on the Reduction of Possibilist Discourse,” in J. E.
Tomberlin
and P. Van
Inwagen, eds., Alvin Plantinga, Dordrecht: D. Reidel Publishing Company:
161-5, 170, 172-3.
Heidegger,
M. (1967) Von Wessen der Wahrheit in Wegmarken.
Fankfurt am Main.
Higginbotham,
J. (1991). “Belief and Logical Form,” Mind and Language, vol. 6: 344-
369.
Iacona,
A. (2003). “Are There Propositions?” Erkenntnis, vol. 58: 325-351.
Menzel, C.
(2008). Problems with the Actualist Account. Stanford Encyclopedia of Philosophy.
Planting, A. (2006) “Why Propositions
Cannot be Concrete,” in Essays in the
Metaphysics of Modality. Ed. Davidson, M. Oxford University Press: 229, 230; Cf. (1993) Warrant and Proper Function. Oxford University Press: 118, 119.
Plantinga, A.
(1974). The Nature of Necessity. Oxford: Oxford University Press.
Tarski, A. (1944). Philosophy
and Phenomenological Research vol. 4.
Van Inwagen, P. (1983). An Essay on Free Will. Oxford
University Press.
[1] I suspect that propositions are the same thing as what philosophers sometimes call ‘abstract states of affairs’. Thus, I suspect that sentences propose states of affairs: for example, ‘John is tall’ is a proposal of the state of affairs of John’s being tall. That same state of affairs may be picked out from a different perspective: for example, ‘the proposal that ‘John is tall’ expresses’; or, ‘the proposition that John is tall’. If that’s right, then the property of obtaining will have the same analysis as the property of being true, namely, correspondence to reality.
[2] For Tarski, a “proposition”, understood as the primary bearer of truth, is a class of sentence tokens (1994, p. 14, footnote 5).
[3] Armstrong (1997, p. 131, 188) takes propositions to be classes of mental state tokens, where classes are spatially located. More recently (2004, p. 15-16), he favors the view that propositions are instantiated properties of beliefs or sentences. In either case, propositions are spatially situated.
[4] I’ll stipulate that sets of objects in causally isolated spatio-temporal worlds (a.k.a., Lewis propositions) don’t count as spatial particulars. Concrete is restricted to objects that fit into a single world.
[5]
Such an inference is, strictly speaking, valid only for so-called intersective adjectives. An adjective is
intersective if applying an adjective-noun complex that contains it, such as ‘a
red car’, to an individual intuitively entails applying the adjective in that
complex (‘red’) to that individual and applying the noun in that complex
(‘car’) to that same individual. By this test, ‘true’, appears to be
intersective since applying the adjective-noun complex, ‘a true proposition’,
to a thing intuitively entails applying ‘true’ and applying ‘a proposition’ to
that same thing. By contrast, ‘fake’ and ‘former’ are examples of
non-intersective adjectives.
[6] For more on this point, see Objection 2 below.
[7] For a reply to the suggestion that serious actualism is false, see Objection 2 above.
[8] See Plantinga (1974, p. 70-71).
[9] If we give that analysis, then we probably should say that ‘those thoughts are the same thought’ is equivalent to ‘those thoughts have the same propositional content’.
[10] This theory of aboutness also may provide a helpful framework for a theory of meaning and reference: for example, if words are stipulated to signal (call up, bring to mind) concepts, then we might say (i) a word refers to whatever the concept signaled by it is about (or to whatever the concept stipulated to be signaled by it is about); (ii) a word expresses the haecceity that is part of the concept signaled by it; (iii) two words mean the same thing if and only if they express the same thing; (iv) sentences are built from words, and they signal thoughts; (v) a sentence refers to an arrangement that the thought it signals is about; (vi) a sentences expresses a proposition that the thought it signals contains as a part; (vii) two sentences mean the same thing if they express the same proposition.
[11] Here is an alternative definition: ‘x is a proposition’ =def ‘$y (y is a level C category, x is a member of y, $z (z exemplifies y, and z is true).’, where ‘level C category’ is a term from Hoffman and Rosencrans used to express a type of fundamental category whose generality is superseded only by the categories, Abstract, Concrete, and Entity. Someone may prefer this definition, but I will not discuss it, given that I no know simple way to define ‘level C category’.
[12] If someone does treat ‘proposition’ as primitive, then she may define ‘entailment’ in terms of ‘proposition’ as follows: ‘x entails y’ =def ‘there is a r (for all p, there is a q (if p and q are propositions, then p stands in r to q), <p and q> stands in r to p, and x stands in r to y).