This is a long, wide-ranging, difficult to understand post. It will be easier to understand in connection with other posts, some of which already exist and are linked to, some of which have yet to come.
There is an irritating issue with some typical examples of the necessary a posteriori. This issue has to do with
existence, negation and presupposition. The purpose of this post is to investigate what our options are with respect to this issue.
Kripke raises the issue and says some things about it in Lecture III of Naming and
Necessity:
One qualification: when I say 'Hesperus is Phosphorus' is necessarily
true, I of course do not deny that situations might have obtained in
which there was no such planet as Venus at all, and therefore no
Hesperus and no Phosphorus. In that case, there is a question whether
the identity statement 'Hesperus is Phosphorus' would be true, false,
or neither true nor false. And if we take the last option, is
'Hesperus = Phosphorus' necessary because it is never false, or
should we require that a necessary truth be true in all
possible worlds? I am leaving such problems outside my considerations
altogether. If we wish to be somewhat more careful, we could replace
the statement 'Hesperus is Phosphorus' by the conditional, 'If
Hesperus exists then Hesperus is Phosphorus', cautiously taking only
the latter to be necessary. Unfortunately this conditional involves
us in the problem of singular attributions of existence, one I cannot
discuss here.
So, the issue lies, in the first instance, with canonical Kripkean
examples of the necessary a posteriori involving names
referring to objects which exist contingently. Besides the example of
empirical identity statements, this also affects, for example,
subject-predicate statements ascribing what we might think of as
necessary properties to contingently existing individuals, e.g. 'N is
spatiotemporal' where 'N' names some physical object.
Kripke's Gappy Option
Since Kripke is talking of necessity in terms of truth-values at
possible worlds, the issue for him involves the question of
truth-value gaps. If the cases in question fall into truth-value gaps
when their putative referents don't exist, then we can take the
option of using 'necessary' to mean 'not false in any possible
world', and these cases come out necessary without having to replace
them with conditionals whose antecedents assert the existence of the
putative referents. Call this 'Kripke's gappy option'.
Kripke's gappy option is quite open to controversy, since the idea
that such sentences fall into truth-value gaps when their putative
referents don't exist may be, and has been, resisted. If there is no
King of France, is 'The King of France is bald' false (as Russell
held), or neither true nor false (as Strawson held)? If there is no
Santa, is 'Santa Claus came to my house and spoke to me yesterday'
false, or neither true nor false? I am not sure that this is a
sensible or important question – isn't there perhaps room for quite
harmless stipulation either way here?, and isn't there room to quite
harmlessly just not care (compare “don't care cases” in computer
science)? – but for what it's worth, I am inclined to think it's
more plausible that the definite description case is neither
true nor false, than it is that the Santa case (a proper name
case) is neither true nor false. It seems very natural to me to call
the Santa sentence false. And since it is proper name cases that we
have to do with, Kripke's gappy option seems predicated on something
quite open to doubt and controversy.
The Conditionalizing Option
The other option Kripke identifies is to give up the idea that
'Hesperus is Phosphorus' and the like are strictly speaking
necessary, and to replace these examples with conditionals like 'If
Hesperus exists, then Hesperus is Phosphorus'. Call this 'the
conditionalizing option'. Kripke shies away from this, saying that it
'unfortunately' involves us in the problems of singular existence
attributions. To contemporary philosophers, this probably doesn't
seem like much of an obstacle; OK, so there might be difficult
philosophical problems pertaining to singular attributions of
existence, but surely we can understand and legitimately use them,
and so this strategy doesn't really involve us in the problems
of singular existence attributions in any urgent way. It seems that
things looked different when Kripke was lecturing, however – in
large part because those very lectures had not yet had their great
effect. The above-quoted passage continues thus, shedding light on
this:
In particular, philosophers sympathetic to the description theory of
naming often argue that one cannot ever say of an object that it
exists. A supposed statement about the existence of an object really
is, so it's argued, a statement about whether a certain description
or property is satisfied. As I have already said, I disagree. Anyway,
I can't really go into the problems of existence here.
The conditionalizing option is more open to us, however, since
singular existence statements are now widely conceded to be
legitimate and understandable, and furthermore because I do go
into the problems of existence, and try to deal with them (for a start, in this post) – and so, to any extent that the conditionalizing option does
involve us in these problems, that isn't a bad thing at all, since
they are being dealt with.
So the conditionalization option is viable. But is it the only
option? We may feel that there is another – that, by construing or
modifying our account of necessity in some simple way (which may take
some finding), we can have 'Hesperus is Phosphorus' itself come out
necessary.
This is somewhat desirable, since a lot of people call that
proposition necessary, without any implicit intention to really
be talking about the conditionalized version, and it seems more
plausible that they have their concepts arranged in a way that makes
what they say true, than to suppose that they are simply mistaken.
But even apart from that, and apart from any considerations in favour
of preferring an account on which 'Hesperus is Phosphorus'
comes out necessary, it is instructive to see whether and how we
might have one. If we get one, we've just enriched our conceptual
resources – we then have (at least) two notions available, closely
related, which we can use 'subjunctively necessary' for – or we can
use two different terms. (We may ask which one best fits most extant
uses of the relevant terminology in the philosophical literature, but
I can't see that this is an especially important question.) We will
now pursue this.
Options Arising on My Account of Necessity
I say that a proposition is necessary iff it is, or is implied by, a proposition which is both true and inherently counterfactually invariant.
In the context of my account of necessity, the issue we have
been discussing does not come so inevitably upon the issue of
truth-value gaps, since I do not give my account of necessity in
terms of truth-values at possible worlds. Truth-values are involved,
of course: to be necessary, a proposition must be true – it must
be, or be implied by, a true and inherently counterfactually
invariant proposition. But the bit which does all the special work,
the notion of inherent counterfactual invariance, is not spelt out in
terms of truth-values, but rather in terms of negation and the
contents of counterfactual scenario descriptions: a proposition is
inherently counterfactually invariant if it is such that, if one
comes to believe it, its negation does not appear in any
counterfactual scenario description permitted by one's system.
Thus, with the account given here, the issue becomes about negation
and the space of counterfactual scenario descriptions permitted by a
system. We will first consider the option of approaching the issue
via negation, in particular, by disambiguating the reference to 'its
negation' – the negation of a proposition – in the
characterization of inherent counterfactual invariance rehearsed
above. On one reading, the cases at issue will come out necessary, on
another, contingent.
Following that, we will consider the option of approaching the issue
via the space of counterfactual scenario descriptions held to be
relevant to inherent counterfactual invariance, and considering a
restriction on this space such that, if it is in place, the cases at
issue come out necessary, and contingent otherwise. One reason for
considering this as well as the (more natural, I think) negation
approach is that the idea that 'not' is ambiguous, or even the idea
that a proposition can be negated in more than one way, is
controversial. I will defend this idea, but even given its
correctness, it may be dialectically useful to have another approach
available, and it is interesting in any case to see that there is
such an alternative.
Internal and External Negation
What is the negation of 'Hesperus is Phosphorus'? Two sentences we
might give are 'Hesperus is not Phosphorus' and 'It is not the case
that Hesperus is Phosphorus'. Is there more than one natural reading
for these sentences? That is, can we give them different natural
readings, or give one of them more than one natural reading?
It seems we can. It seems particularly clear that we can give one
natural reading to one of them, and another to the other: we can read
the first as implying that Hesperus (and perhaps a distinct object
Phosphorus) exists, and read the second as having no such
implication. Consideration of cases involving empty names (i.e.,
where the relevant existence-implications will be false) gives this
intuitive support; if someone says 'Santa's not happy', we might take
this as saying that Santa's state of mind is not a happy one – that
is, we might understand it to be saying something which, in order to
be true, requires that Santa exists. If someone says 'It is not the
case that Santa is happy', we might understand this as having no such
requirement – roughly, as merely denying that it is true to say
that Santa is happy. It may also be that one of these sentences can
naturally be understood both ways, or that both can (whether or not
we should say this will not concern us here).
So, it seems natural to suppose that we have here a difference
between two kinds of negation of a proposition, and should therefore
regard the phrase 'the negation' as ambiguous, or as failing to refer
due to a failure of uniqueness. Let us for now use, in a rough way,
the terms 'internal negation' and 'external negation' to talk about
these two kinds, in advance of any particular account of how negation
works in the different cases, or how the difference gets made, and
without assuming that there aren't further distinctions to be made,
for example between different sorts of internal negation. We will now
consider some different strategies for accounting for this
distinction.
Internal Negation as
Dispredication
Looking at 'Santa is not happy' and 'It is not the case that Santa is
happy', we might have the idea that the difference between them
consists in this: that the first purports to name Santa and deny the
predicate 'is happy' of him, much as 'Santa is happy' affirms it,
whereas in the second case the negation applies to the whole
proposition about Santa. Thus the first cannot be true without Santa
existing, while the second can.
We may think of these two propositions as being of different logical
forms. The first is of the subject-predicate form (or, we might say,
a closely related dispredicational form) whereas the second is a
truth-functional compound with one argument. On this way of
construing the latter, the phrase 'It is not the case that' is taken
as forming a symbol, so that the proposition may be rewritten
'Not-(Santa is happy)' or '~(Santa is happy)'.
Alternatively, we may think of external negation in natural language
propositions like 'It is not the case that Santa is happy' as a
special case of internal negation, namely where the subject is a
proposition (or proposition-meaning, or whatever is apt to be the
case) which is specified with a that-clause. And so while 'It is not
the case that p' propositions are equivalent, and effectively
the same as, those of the more artificial operatorial forms, we
really only need internal negation, and the difference between 'Santa
is not happy' and 'It is not the case that Santa is happy' is that
the subject of the first is Santa, and the subject of the second is
this 'It' – that Santa is happy. The first dispredicates happiness
of Santa. The second dispredicates being the case of a certain
proposition, or proposition-meaning (including both internal meaning
and external projective relations), or whatever being-the-case-apt
thing it is, and could be rendered without the 'It' as 'That Santa is
happy is not the case'. (Note that not all similar-looking forms can
easily be regarded as having the same kind of subject. For
example, 'It is good that …'. It seems that for 'It is not
good that p' to be true, 'p' needs to be true. We might
say that the subject here is a state of affairs or a fact.)
Irrespective of this alternative regarding external negation, we have
a problem with internal negation. The trouble with the
dispredicational approach to internal negation lies in generalizing
it. Recall that our aim is to spell out a distinction between two
kinds of negation of a proposition, internal and external, so that
cases like 'Hesperus is Phosphorus' come out necessary on our account
if we use one sort of negation in our characterisation of inherent
counterfactual invariance, and contingent if we use the other. It
will be internal negation which yields the former verdict, external
which yields the latter; since there are no counterfactual scenarios
where Hesperus exists and fails to be Phosphorus, the internal
negation of 'Hesperus is Phosphorus' should not be part of any
counterfactual scenario description. But since there are
counterfactual scenarios where Hesperus doesn't exist, the external
negation can appear in descriptions of those.
For this strategy, as outlined, to work, it will have to be the case
that every proposition has an internal and an external negation. For
the notions of necessity and contingency, and therefore our special
notion of inherent counterfactual invariance in terms of which we
define them, are meant to apply (positively or negatively, and
borderline cases aside) generally to all kinds of propositions.
The only other options I can see, short of denying modal status to
some propositions of a non-borderline sort which seem to have modal
statuses, are the following variations on the strategy as outlined:
(i) simply stipulate some modal status for all truths and for all
falsities for which there is no internal negation (or for which
'internal negation' is undefined), (ii) take a disjunctive approach
to counterfactual invariance (and in turn necessity) by making the
internal negation of the proposition in question the relevant thing
when there is one, the external negation otherwise. Neither of these
seems very appealing, and below we will encounter reasons for
thinking that, in addition to seeming ad hoc and messy, they
do not behave in any satisfying way: (i) will wind up giving
intuitively wrong answers about a great many propositions to which
the dispredicational account of internal negation does not apply
(such as quantifications, to anticipate), and (ii) will yield an
account which behaves in a way which intuitively seems unsatisfyingly
non-uniform, even if every verdict it gives is correct on some
natural, intuitive understanding of the modal notions.
So, how might we extend the dispredicational account of the
distinction between internal and external negation so that it gives
all propositions both an internal and external negation?
The case of external negation presents no difficulties on this score,
whether or not we regard it as a special case of internal. Every
proposition can have the truth-functional negation operator applied
to it, and every proposition (or proposition-meaning, or whatever)
can be made the subject of an 'It is not the case that p'
proposition.
But what are the internal negations of propositions which do not seem
to be of the subject-predicate form supposed to be? We will consider
three classes of such propositions: relational propositions,
truth-functions, and quantifications.
Relations. We began by considering 'Hesperus is Phosphorus',
which is often construed relationally, as an ascription of the
identity relation. We are perhaps able to stave off, as far as
identity statements go, the problem of extending our dispredicational
account of internal negation; in other posts we considered issues
which arise when identity is construed as a relation, and offered an
alternative construal of identity statements as subject-predicate
propositions of a special kind. But that is small comfort, since we
must face the issue anyway – we will certainly need to be able to
use our account of internal negation to rule some relational
statements about contingently existing individuals to come out
necessary, others contingent, others impossible, others contingently
false. (Consider: 'Hesperus is in the same location as Phosphorus' -
necessary if colocation is reflexive, 'Hesperus is near Mars' -
contingently true on a suitable construal of 'near', 'Hesperus is in
a different place from Phosphorus' – impossible, 'Comet A fell to
Hesperus' – could be contingently false.)
So, what might the internal negations of 'John loves Mary' and 'John
told Paul about Mary' be?
One simple enough option is to treat these as subject-predicate
propositions, with 'John' as the subject, and 'loves Mary' and 'told
Paul about Mary' as the predicates, and then treat their internal
negations as simple dispredications. But the results will not require
Mary (and in the second case, Paul as well) to exist, as they might
if construed differently. On different ways of construing them
(according to whether we have just one subject, or two or more, or
equivalently how we construe the predicate (how many places, and
where)) their counterfactual invariance status may vary. But if the
positive statements being negated all imply each other under these
various construals, even if their negations don't, then these
differences will not “percolate up” to necessity and other modal
statuses. Nevertheless, we have got ourselves into a messy situation,
and the dispredicational approach is not looking very appealing, even
if it can be argued to happily deliver the desired results. I will
try to unpack this a bit, before moving on to consider how the
dispredicational approach to internal negation might be extended to
truth-functions.
Suppose 'If a and b exist, then aRb' is
necessary on an external negation construal of counterfactual
invariance, and suppose a and b are distinct,
contingently existing and independently existing things. Now, we want
a dispredicational construal of the internal negation of 'aRb'
such that this comes out necessary when we make that the relevant
negation for counterfactual invariance. Since a and b
exist contingently and independently of each other, we can divide
counterfactual scenarios into four kinds. Using 'a' in this
sentence to mean 'a exists' and '~a' to mean 'a does
not exist', we have scenarios in which (i) a & b,
(ii) ~a & b, (iii) a & ~b, and
(iv) ~a & ~b.
Now, let us consider what happens when we take 'a' in 'aRb'
as subject and 'Rb' as predicate, i.e. when we construe 'aRb'
as 'a is (R b)'. The internal negation of this, which
in effect says that a lacks the (non-contingently existing)
property of bearing R to b, can appear in descriptions of
scenarios of type (iii); when b doesn't exist but a
does, a must lack that property, since possessing it would
require b to exist. And so on this constual, 'aRb'
is not counterfactually invariant – its internal negation does
appear in counterfactual scenarios permitted by the system to which
it belongs.
On the other hand, when we take a and b both as
subjects, or for clarity and neatness's sake the ordered pair <a,
b>, i.e., when we construe 'aRb' along the
lines of '<a, b> (falls under R)', we get a
different result. Instead of saying that a lacks the property
of being R-related to b, this says in effect that the pair of
things a and b lack the property of falling under R. So
this cannot appear in scenarios of type (iii), since that pair
doesn't exist in those scenarios. On this construal, therefore, 'aRb'
is counterfactually invariant.
(Note that this divergence doesn't show up with true identity
statements, even when we do construe them relationally, since in
their case the categories (ii) and (iii) will be empty.)
It may seem that, since 'aRb' differs on these
construals with respect to counterfactual invariance status, it must
differ with respect to necessity vs. contingency as well. After all,
this is not one of the disjunctive sorts of cases which was seen to
motivate the closure of necessity under implication in my account of necessity, and so it
may seem like propositions like 'aRb' are necessary
only if they themselves are counterfactually invariant, and since
'aRb' isn't counterfactually invariant on one of its
construals (namely 'a is (Rb)'), it isn't necessary on
that construal either.
This can, and arguably should, be resisted, on the grounds that the
'<a, b> (falls under R)' construal implies the 'a
is (Rb)' construal. Indeed, they very arguably imply each
other, even though their dispredicational internal negations do not.
And so, while 'aRb' on the 'a is (Rb)'
construal is not counterfactually invariant, it is implied by a
proposition ('aRb' on the '<a, b>
(falls under R)' construal) which is both counterfactually invariant
and true, so it comes out necessary.
Nevertheless, all this complication is unpleasant – these multiple
ways of grouping relational statements into subject, or subjects, and
predicates don't seem very instructive, and what they are capturing
might plausibly be expected to be capturable in a more illuminating
way. (To anticipate, I will end up suggesting that we do this by
considering the way a proposition may be construed as having more or
less presuppositions.)
Truth-functions. This could perhaps be dealt with by laying it
down that, to obtain the internal negation of a truth-functional
proposition, one must translate it into disjunctive normal form (a
disjunction of conjunctions of non-truth-funcional propositions or
negated non-truth-functional propositions) or conjunctive normal form
(a conjunction of disjunctions of atomic non-truth-functional
propositions or negated non-truth-functional propositions), and then
give each negated non-truth-functional proposition an internal
reading.
For example, the internal negation of 'p or q', then,
will be, taking the option of disjunctive normal form, '(p and
q) or (<p's internal negation> and q) or
(p and <q's internal negation>)'.
Presupposing that internal negation is defined for all
non-truth-functional propositions, we can extend the definition to
truth-functions in this artificial way. The artificiality of this
procedure compared with the account of internal negation we will
eventually settle on is a reason for favouring the latter, but this
will be overshadowed by problems arising in the consideration of
quantifications below.
Quantifications. So far, we have been able to wangle, using
fairly elaborate means, extensions of the dispredicational account of
internal negation to relations and truth-functions. But the account
founders more seriously on quantifications.
Consider, for example, the proposition 'There are feathers in Robin
Hood's cap'. It seems we can say 'There are no feathers in Robin
Hood's cap' and read this as requiring Robin Hood's existence –
effectively, asserting the featherlessness of Robin Hood's cap. And
on the other hand it seems we can say 'It is not the case that there
are feathers in Robin Hood's cap', and read it as making no such
requirement.
(It may be protested that 'There are no feathers in Robin Hood's cap'
can be dealt with by regarding 'no' not as a negation sign, but as
like a number-term, making the proposition effectively the same as
'There are zero feathers in Robin Hood's cap'. That is plausible
enough for this particular case, but consider 'There aren't feathers
in Robin Hood's cap', or this exchange: A: 'There are feathers in
Robin Hood's cap', B: 'There are not!'.)
I do not think we can extend the dispredicational approach to
internal negation to cover this case, but let us consider two routes
which may present themselves: (i) treating quantifications in a way
inspired by Frege and Russell as second-order predications, and (ii)
treating quantifications as infinite conjunctions or disjunctions.
Both Frege and Russell had a version of what Scott Soames calls a
'properties of properties' analysis of quantification. The
basic idea, in formal logical terms, is first to abstract a property
from the open sentence bound by the quantifier and then to see the
quantifier itself as predicating of that property, in the case of
universal quantification, the property of being possessed by
everything, or in the case of existential quantification, the
property of being possessed by something.
In simpler terms, 'Everything is F' (i.e. 'Everything has the
property F') is analyzed along the lines of 'being F is
possessed by everything', i.e. a subject-predicate
proposition. Or to take a slightly more complicated example, 'All men
are mortal' is analyzed along the lines of 's is P', where 's'
denotes the set of things which are such that, if they are men, then
they are mortal, and 'P' is a predicate true of properties which are
possessed by everything.
Brilliant and insightful as this is, it doesn't meet our present
needs, since the subject here will always be a property. What we
needed was an ability to make contingently existing things whose
existence is presupposed by the proposition in question the subjects.
So a proposition like 'There are no feathers in Robin Hood's cap', if
this is taken to presuppose the existence of Robin Hood, cannot be
rendered in this way, at least not without regarding the property of
being a feather in Robin Hood's cap to be a contingently existing
thing, which would be controversial and difficult. (We will come back
to this example below and discuss it a bit further, when we consider
and reject the option of a disjunctive approach to inherent
counterfactual invariance, whereon the internal negation is what is
relevant when there is one, the external negation otherwise, such as
in quantificational cases.)
What about the second option of analyzing quantifications as infinite
truth-functional propositions – universal quantifications as
infinite conjunctions, and existential quantifications as infinite
disjunctions? It is a commonplace in contemporary analytic philosophy
that this doesn't work – the treatment of them as such by the
Tractatus, for example, is widely regarded as one of the
fundamental flaws in the Tractarian system.
Why exactly it doesn't work – or, how best to argue that it doesn't
work – is actually not nearly so clear and well-established as that
it doesn't work. I will not try to give a full treatment of this
matter here, but I will briefly look at one quite natural but bad
argument that it doesn't work, before discussing why it doesn't work
from my point of view.
The natural but bad argument I want to consider is instanced by
Richard Holton and Huw Price in 'Ramsey on Saying and Whistling: A
Discordant Note', where they consider a reconstruction of one of
Ramsey's arguments for treating quantificational sentences as not
being (or expressing) genuine propositions. The argument proceeds via
an argument that they cannot be treated as infinite conjunctions or
disjunctions. Here is the reconstruction, with a good criticism
following it:
If
we treat universally quantified sentences as expressing propositions
we will be forced to see them as equivalent to conjunctions which,
since they are infinite, ‘we cannot express for lack of symbolic
power’. But that is no good: ‘what we can’t say we can’t say,
and we can’t whistle it either’.
Is this argument
convincing? At first sight, apparently not, for consider an analogy.
What do you get if you divide one by three? If you try saying the
result as a decimal expansion you will never stop: 0.33333...
However, that doesn’t mean that you can’t say it, only that you
need to express it in a different way: as the fraction 1/3.
Holton and Price go on to consider another interpretation of Ramsey,
which brings the argument closer to other arguments he gave for the
same conclusion. We won't bother with that; our motive was largely to
bring into focus that appealing to our finitude, our limitations, in
resisting the infinite truth-function analysis of quantifications
isn't the point.
What is the point? From my point of view, we can distinguish
eight angles from which to see that the truth-functional analysis of
quantification fails. For four of these (namely (1), (2), (6) and
(8)), I will draw on Wittgenstein's discussion of 'Generality' in
Philosophical Grammar (part II, section II, pages 257 –
279), which includes a subsection called 'Criticism of my former view
of generality', this former view being the truth-functional analysis
of quantification as given in the Tractatus.
(1) Phenomenology of sense: It just doesn't seem like a
simple existential quantification (for example), such as 'There are
horses', means the same as some long, or infinite, disjunction. We
feel like the particular disjuncts in such a disjunction deal with
cases, and that these cases to not enter into the sense
of the quantification. The quantificational proposition is simple,
whereas the long disjunction is complicated.
Here are three passages from
Philosophical Grammar which
express this point:
Let us take the particular
case of the general state of affairs of the cross being between the
end-lines.
|--X------| |-----X---| |-------X-| |---X-----|
Each of these cases, for instance, has its own individuality. Is
there any way in which this individuality enters into the sense of
the general sentence? Obviously not. (p. 257)
There is one calculus containing our general characterization and
another containing the disjunction. If we say that the cross is
between the lines we don't have any disjunction ready to take the
place of the general proposition. (p. 258)
Suppose I stated a disjunction of so many positions that it was
impossible for me to see a single position as distinct from all those
given; would that disjunction
be the general proposition (Ex).Fx? Wouldn't it be a kind of pedantry
to continue to refuse to recognize the disjunction as the general
proposition? Or is there an essential distinction, and is the
disjunction totally unlike the general proposition?
What strikes us is that the one proposition is so complicated and the
other so simple. … (p. 262)
(2) Favourable cases are clearly special: Cases which do seem
to have justice done to them by the truth-functional analysis of
quantification are clearly special – they clearly fulfil
conditions which aren't generally fulfilled by quantifications. So,
by applying the Wittgensteinian method (made explicit later, in the
Investigations) of considering 'a language-game for which this
account is really valid' (PI, 48), we will be able to see that
the account is not generally valid, since its validity in the
favourable cases turns on features not shared by all quantificational
propositions.
Of course it is correct that (Ex)Fx behaves in some ways like a
logical sum and (x)Fx like a product; indeed for one use of
the words “all” and “some” my old explanation is correct, -
for instance for “all the primary colours occur in this picture”
or “all the notes of the C major scale occur in this theme”. But
for cases like “all men die before they are 200 years old” my
explanation is not correct. (p. 268)
These amenable cases are clearly special; what makes them amenable is
the fact that the concept terms 'primary colour' and 'note of the C
major scale' determine, by their very meaning (or 'grammar'), their
extensions. Any term used in such a way that something other than {C,
D, E, F, G, A, B} (where these letters are taken as names of notes)
is its extension simply wouldn't express the concept of a note of the
C major scale. Clearly, not all quantifications involve such concepts
– for example, the one about men all dying before the age of 200
doesn't. From this we can see that the truth-functional analysis
isn't generally valid.
(3) The “that's all” problem: Suppose there are just three
objects, a, b and c. (This is just for
simplicity's sake – the problem I which will now emerge could be
stated for the case of reality, too.) Now, on the basic
truth-functional analysis of quantification, 'Everything is F' means
'a is F and b is F and c is F'. But suppose
someone believes falsely in a fourth object, which they call 'd'.
Surely believing in an object which doesn't exist doesn't stop them
correctly understanding 'Everything is F', and using it with its
actual meaning. But if they thought d wasn't F, they would
deny that everything is F, but they may consistently accept that a
is F and b is F and c is F.
This actually enables us to see two problems: the present “that's
all” problem, and the next problem on our agenda, the problem of
meaning varying with the domain.
The “that's all” problem is this: the conjunction above doesn't
capture the meaning of 'Everything is F' because it leaves it open
whether there are other objects not mentioned by it – it lacks a
“that's all” implication.
This shows the basic truth-functional analysis of quantification,
exemplified above, to be wrong. But what if the “that's all”
problem could somehow be solved?
There are three sorts of attempts at solutions to consider:
(i) Attempts which deny the need for quantification propositions,
upon analysis, to say anything to the effect that “that's
all”.
(ii) Attempts to modify the analysis so that quantificational
propositions somehow have a “that's all” implication, while
preserving non-circularity.
(iii) Attempts to modify the analysis by adding a “that's all”
clause, without trying to avoid circularity.
Wittgenstein in the Tractatus is the representative of (i)
which I have in mind. The dilemma I propose for this approach is:
either there is something deeply right about Wittgenstein's
contention that it is nonsensical to name a bunch of objects and say
that they are all the objects that there are, or there isn't.
If there is (as I suspect), then this just shows the whole
truth-functional approach to quantification to be wrong: many
quantificational propositions clearly do say everything they
try to say. While it may be important to see that certain “that's
all” type propositions are really pseudo-propositions, this
appearance of an unsayable element which we may try, and inevitably
fail, to express in a proposition, obviously doesn't percolate up to
quantificational propositions, as it would if the analysis were
correct. It is simply beyond the pale to say that all
quantificational propositions involve this sort of “nonsense”, or
this attempt to say what can only be shown, or whatever it is, and
equally beyond the pale to say that they show something along “that's
all” lines which we may try and fail to say – to bite the bullet
on this would be to embrace a cripplingly narrow view of the typology
and functioning of propositions.
If there isn't, then this sort of attempt is misguided
through-and-through.
The second sort of attempt, modifying the analysis to get a “that's
all” implication, but without circularity, seems to me to be
a non-starter. It may perhaps be argued that this might just be due
to a failure of imagination on my part, but I'm inclined to think
this isn't so, and that considerations along the lines of the Paradox
of Analysis would apply to any materially adequate attempt: any
linguistic device able to pull off the trick of giving you a “that's
all” implication would thereby qualify as a quantificational
device, and so no analysis pulling off this trick could possibly be
non-circular.
The third sort of attempt is interesting; perhaps an analysis of
quantification in terms of a truth-function with a “that's all”
clause tacked on may be true, even if the “that's all” clause
involves quantification, making the analysis circular; it may be a
non-vicious circularity. Furthermore, the analysis may answer to the
task of explaining how quantificational propositions may have
dispredicational internal negations: the negation would now apply to
a truth-function involving (what may be unnegated) quantification,
rather than directly to a quantification, and so the artificial
strategy suggested above for getting dispredicational internal
negations of truth-functions may apply.
This third attempt is in many ways the most promising – the others
seem quite hopeless. At least we get an analysis here,
something which we can work with and assess, and one which clearly
doesn't suffer from the “that's all” problem. But this
attempt brings out the fact that our example above of someone who
believes in something which doesn't exist, but still gives
quantifications the right meaning, shows up two further problems: the
problem of excess content, and the problem of meaning varying with
the domain. These show the truth-functional approach to be wrong,
with or without a circularity-making “that's all” clause.
(4) The problem of excess content: with the “that's all”
problem above, we were entertaining considerations which suggest that
the truth-functional approach to quantification yields analyses which
aren't logically strong enough in a certain respect: they fail
to imply that there is nothing else in the world not covered by the
proposition. But there is an opposite problem as well: the analyses
yielded are too strong in certain respects, having
implications which the propositions they are meant to be analyses of
do not have.
For example, 'All men are mortal', if analyzed as an conjunction with
a conjunct for every thing, saying that that thing is either mortal,
or not a man, then it would involve, for example, a conjunct saying:
Venus is either mortal, or not a man. And this implies that Venus
exists. But 'All men are mortal' doesn't imply that Venus exists, so
the analysis is wrong.
This holds whether or not we have a “that's all” clause. If we
do, the problem just gets worse: not only is 'All men are mortal'
falsely predicted to imply, of any existing thing you care to
mention, that that thing exists, it is also falsely predicted to say
that there is nothing besides what it names – in other words, it is
predicted to specify which things exist, which it surely does
not do (no matter how deeply you analyze it!).
(5) The problem of meaning varying with the domain:
This problem is, in the abstract, that a truth-functional analysis of
quantification falsely predicts that the meaning of quantificational
propositions varies with the domain.
Suppose (again, for simplicity's sake) that there are just three
things, a, b and c. On the truth-functional
approach, 'Everything is F' can now be analyzed as 'a is F and
b is F and c is F' (or perhaps this with a “that's
all” clause added).
The problem can now be seen from an epistemic (or doxastic) angle:
suppose someone in this three-object world believed falsely in a
fourth object, d, then they wouldn't accept the analysis, and
yet intuitively they might understand 'Everything is F' just as well
as we do, be just as good at analysis, and mean the exact same thing
by it.
If we take a temporally dynamic view of existence, it can also be
seen from the angle of the domain changing over time: 'Everything is
F' doesn't mean 'a is F and b is F and c is F',
since, if something new, d were to come into existence and
come to our attention, and if we didn't know whether it was F yet, we
wouldn't say 'Everything is still F, according to what we used to
mean by that'. Rather, we would bring the question of whether d
is F to bear on our proposition 'Everything is F' without it
having changed its meaning.
What about if we had a “that's all” clause? In that case, if the
analysis were right, and we carried on using 'Everything is F' with
the same old meaning (not changing it to cover d), the mere
existence of d ought to make us judge it false (since you can
no longer say “that's all” of a, b and c taken
together). But in fact, we don't change its meaning, but we don't
just it false just in view of d's existence either.
Finally, we can see the problem from a counterfactual or “other
worlds” angle: our proposition 'All men die before the age
of 200', with the meaning it has, may be true of circumstances in
which some things which actually exist don't exist (i.e. where the
domain varies). But if the truth-functional analysis were right, it
would come out false: if some actually existing thing a failed
to exist in these circumstances, then in the analysis of 'All men die
before the age of 200', the conjunct which covers a, and says
of it that it either dies before 200 or isn't a man, would come out
false, falsifying the whole. But that is clearly not how the
proposition analyzed works: we can speak of counterfactual scenarios
in which all men die before the age of 200, but in which you or I
don't exist.
(6) The problem of the relevant propositions not existing: On
this approach, the infinite conjunctions and disjunctions we would
need just don't exist, or even cannot exist – and not just because
they are infinite. Rather, also because they would have to contain
propositions which name objects, where there just aren't any such
propositions, and perhaps couldn't be.
Here is Wittgenstein's expression of this point in Philosophical
Grammar:
Criticism of my former view of generality
My view about general propositions was that (Ex)Fx is a logical sum
and that though its terms aren't enumerated here, they are
capable of being enumerated (from the dictionary and the grammar of
language).
For if they can't be enumerated we don't have a logical sum.
…
Of course, the explanation of (Ex)Fx as a logical sum and of (x)Fx as
a logical product is indefensible. It went with an incorrect notion
of logical analysis in that I thought that some day the logical
product for a particular (x)Fx would be found. (p. 268)
This point – which is quite well known in a slightly different
guise, namely as a problem for substitutional quantification (which I will discuss in a future post) – is likely to be controversial, since it
relies on taking a certain kind view of the nature and existence of
propositions. This kind of view may be called a “down to earth”
view: propositions are the sort of things which come out of our
mouths and get written down, or types thereof.
Many philosophers think about propositions and the like in ways which
are not down-to-earth in this sense. If, for example, we
conceive of a name with a referent in abstract mathematical terms, as
for example an ordered pair consisting of an abstract typographical
object and an object (the referent), then this problem doesn't really
come through - although another, Benacerraf-esque problem arises:
what's to say which “names” are chosen for the RHS of the
analysis, since if the pair <the letter A, n> exists,
where n is some highly obscure object which no one will ever
really name, and perhaps couldn't, then so too does the pair <the
letter B, n>.
(7) Cardinality problems: If there exists a non-denumerable
infinity of real numbers, for example, then it may be argued that
there are not enough names and propositions to go around – and this
isn't due to our finitude: even infinitely many names and infinitely
many propositions about infinitely many objects may not be enough,
even on an abstract, non-down-to-earth view (in the sense of point
(6) above), if there are only denumerably many names.
(8) The problem of domain indeterminacy: The “universal
domain”, as well as various subdomains of discourse, cannot
(without significant idealization) be regarded as constituting a
determinate totality. Many domains are such that you can talk
literally, without making any idealization, about a determinate,
non-fuzzy set which collects all and only the elements of the domain
together. This may lead us to fail to see that there really is no
such thing in the universal case, and in many subdomains as well.
Despite the idea of a determinate totality being ultimately
chimerical here, that doesn't mean we can't quantify over all things,
or use quantificational propositions in connection with subdomains
not constituted by determinate totalities.
From Philosophical Grammar:
[W]hat matters, I believe, isn't really the infinity of the
possibilities, but a kind of indeterminacy. Indeed, if I were asked
how many possibilities a circle in the visual field has of being
within a particular square, I could neither name a finite number, nor
say that there were infinitely many (as in a Euclidean plane). Here,
although we don't ever come to an end, the series isn't endless in
the way in which | 1, ξ,
ξ + 1 | [Wittgenstein's
sign for the series of positive integers] is.
Rather, no end to which we come is really the end; that is, I could
always say: I don't understand why these should be all the
possibilities. – And doesn't that just mean that it is senseless to
speak of “all the possibilities”? (p. 276)
This seems closely related to the Tractarian idea, which came in in
connection with point (3)(i) above, that you can't actually list a
bunch of objects and sensically say “that's all” of them.
We have now seen eight reasons why quantificational propositions
cannot be analyzed truth-functionally.
We now conclude, then, that there is no satisfactory way to extend
the dispredicational approach to characterising internal negation to
the case of quantificational propositions – it cannot be done with
them as they are, and they cannot be analyzed into a more amenable
form either.
The Presuppositional Account
I propose we account for the distinction between internal and
external negation is in terms of the notion of presuppositions;
'Hesperus is Phosphorus', intuitively, doesn't actually say
that Hesperus/Phosphorus exists, but presupposes it. We can see the
internal negation as preserving this presupposition, and the external
negation as cancelling it. Rather than thinking of this as some kind
of effect of the two sorts of negation, which we would have to
do anyway if we adopted another account of the internal/external
negation distinction, we should use this to characterise the two
sorts, and the difference between them.
We can be more nuanced too and differentiate between, not just cases
where all presuppositions are cancelled and cases where none are, but
cases where some presuppositions are in force and others aren't. In
this way, we can capture what was awkwardly captured on the
dispredicational approach by means of different groupings of
subject(s) and predicate.
This approach to making a meaning-distinction between two sorts of
negation based on the notion of presuppositions is taken up, in a
particular version, by Pieter Seuren in his papers 'Presupposition
and Negation' and 'Presupposition, Negation and Trivalence'.
Seuren's approach involves a third truth-value, since Seuren wants
both internal and external negations to be expressible as unary
truth-functional propositions. Propositions whose presuppositions
fail are 'radically false', while propositions whose presuppositions
are met but which still aren't true are 'minimally false'. This then
leads to several options and complications which Seuren tackles
undaunted.
I want to abstract away from this way of going. Why, for example, do
we need to regard internal negation as a truth-functional
propositional operator? If we don't, then do we really need three
truth-values, or even gaps for that matter? For example, can't we
just distinguish between cases of what Seuren calls the 'radically
false' and the 'minimally false' by taking directly about
presuppositions, or the truth-values of their internal negations,
while calling them all just 'false'?
Our conclusion, then, is simply that we should distinguish two kinds
of negation, internal and external, and that we should characterise
this distinction by means of the notion of presupposition: internal
negation preserves (some or all) presuppositions, and external
negation cancels them.
Negation and Ambiguity
Some linguistic constructions may quite unambiguously be internal or
external negations, other constructions may tend to signal one or the
other, and still other constructions may not carry anything in
themselves to suggest one or the other, this being left to context.
Since I do not want to get deep into the linguistic details of how
things are in these respects, it will be difficult to discuss
questions of potentially controversial ambiguities implied by this
approach with any concreteness. For example, should we say 'not' is
ambiguous on this approach? Or can we avoid this by locating the
difference, not in the meanings of expressions, but their form or
mode of composition? (Or even their subject matter: recall in this
connection the idea adumbrated above of construing external negation
expressed with 'It is not the case that' as dispredicating being
the case of a proposition (or proposition-meaning) referred to by
'It' and the 'that' clause.)
Without going into the details of negation-expressions themselves
(like 'not'), we may still consider questions of ambiguity in two
ways: (i) by considering, in the abstract, the question of how any
ambiguities which may arise on this approach may be made sense of and
legitimized, and (ii) by considering the “meta” but concrete case
of the expression 'The negation of …' where the dots are filled in
with an expression referring to a proposition.
Here is what Seuren has to say about negation and ambiguity:
The
ambiguity of negation in natural language is different from the
ordinary type of ambiguity found in the lexicon.
Normally, lexical ambiguities are idiosyncratic, highly contingent,
and unpredictable from language to language. In the case of negation,
however, the two meanings are closely related, both
truth-conditionally and incrementally. Moreover, the mechanism of
discourse incrementation automatically selects the right meaning.
These properties are taken to provide a sufficient basis for
discarding the, otherwise valid, objection that negation is unlikely
to be ambiguous because no known language makes a lexical distinction
between the two readings.
While Seuren and I are in agreement that we can profitably speak of
an ambiguity between internal and external negation, I want to say
that the case of negation is not so special as these remarks of
Seuren's may make it seem.
Indeed, the topic of negation just provides another case, or bunch of
cases, of ambiguities which fail the Kripke test (roughly: when faced
with the question of whether an expression is ambiguous, look at
whether other languages use two different expressions instead of one
– if not, that casts doubt on the ambiguity).
I will dicuss ambiguities failing
the Kripke test, in connection with semantic granularity, in a future post, and from that discussion it will be clear that there
is nothing which isn't 'ordinary' or 'normal' here (Seuren's words
for what the case of negation isn't), and that the Kripke-test-based
objection he considers is not 'otherwise valid': there is a large
class of cases for which the Kripke test is valid, and a large class
for which it is not, and granularity considerations can help us see
what characterizes these classes.
Restricting the Space of
Scenarios
There is an alternative to the approach of getting 'Hesperus is
Phosphorus' and the like to come out necessary on my account by defining inherent
counterfactual invariance in terms of internal negation. It is
perhaps a bit less natural, but it may have an ecumenical advantage,
in not requiring there to be an internal/external negation
distinction.
Rather than defining inherent counterfactual invariance in terms of
all counterfactual scenarios, as in:
A proposition is inherently counterfactually invariant iff it is
inherently such that, if you come to believe it, its negation doesn't
appear in any counterfactual scenario description.
We can say:
A proposition is inherently counterfactually invariant iff it is
inherently such that, if you come to believe it, its negation doesn't
appear in any counterfactual scenario description according to
which the presuppositions of that proposition are met.
An Analogous Issue with the
Contingent A Priori,
Treated Differently
Recall that the issue we have been looking at here affect necessary
truths about contingently existing things. There is an analogous
issue with cases of the contingent a priori. When a name, say
'N', has been stipulated to refer to the concrete particular, if
there is one, which fulfils certain conditions F, it is often said
that the proposition 'N is F' will then be contingent a priori.
But this statement entails that N, some concrete particular, exists
(and is F), and surely this cannot be a priori. In this
case, I think there is no very natural other way, and so I simply
deny that such propositions are a priori, speaking strictly.
(There is of course room for a slightly artificial use of 'a
priori' defined in terms of a more natural use with the express
purpose of making such cases come out a priori – e.g.
something is a priori in this special sense iff its
conditionalization (in the sense of the conditionalizing option
discussed above) is a priori.) 'If N exists, N is F', on the
other hand, will be genuinely contingent a priori.
Conclusions
Our main conclusions are as follows. We can distinguish two
construals of inherent counterfactual invariance, so that on one
'Hesperus is Phosphorus' is not strictly speaking necessary (while
'If Hesperus exists, then Hesperus is Phosphorus' is), and on the
other it is. There are at least two viable ways to get the second
construal (and so, you might say, we can really distinguish three
construals, but two of them line up): (i) by means of a distinction
between internal and external negation, where the former preserves
presuppositions and the later cancels them, or (ii) by defining
inherent counterfactual invariance, not in terms of all
counterfactual scenario descriptions permitted by the system of
language to which the proposition in question belongs, but rather in
terms of the subset of permitted counterfactual scenario descriptions
which describe scenarios in which the presuppositions of the
proposition in question hold.
Along
the way, we reached some other conclusions, which may be of
independent interest. One of these was that the dispredicational
approach to the internal/external negation distinction cannot be
satisfactorily extended to all propositions. In the course of seeing
this, we also saw that quantificational propositions cannot be
analyzed as truth-functions, and furthermore, we got a good look at
why not,
distinguishing eight angles from which it can be seen.
