Title: On Denoting
1On Denoting
2Weve got some serious problems
3A Puzzle About Identity
- Indiscernibility of Identicals If a b then
whatever is true of one is true of the other. - If a is identical with b, whatever is true of
the one is true of the other, and either may be
substituted for the other in any proposition
without altering the truth or falsehood of that
proposition. Now George IV wished to know whether
Scott was the author of Waverly, and in fact
Scott was the author of Waverly. Hence we may
substitute Scott for the author of Waverly and
thereby prove that George IV wished to know
whether Scott was Scott. - Problem contexts in which substitutivity salve
veritate fails, e.g. - George IV wondered whether ___ wrote Waverly.
- Necessarily ___ is odd.
4A Puzzle About Excluded Middle
- The Law of Excluded Middle For any proposition,
P, either P or not-P - By the Law of Excluded Middle, either A is B
or A is not B must be true. Hence either the
present King of France is bald or the present
King of France is not bald must be true. Yet if
we enumerated the things that are bald and then
the things that are not bald, we should not find
the present King of France in either list. - Problem When the subject term of a sentence
fails to refer, excluded middle fails, e.g. - The present King of France is bald.
- George W. Bushs son is a plumber
5A Puzzle About Negative Existentials
- A proposition cannot be about a non-entity to be
either true or false the subject term of a
singular statement must refer to something. - Consider the proposition A differs from B. If
this is true, there is a difference between A and
B, which fact may be expressed in the formthe
difference between A and B subsists. But if it
is false that A differs from B, then there is no
difference between A and B, which fact may be may
be expressed in the form, the difference between
A and B does not subsist. But how can a
non-entity be the subject of a proposition?...If
A and B do not differ, to suppose either that
there is, or that there is not, such an object as
the difference between A and B seems equally
impossible. - Problem Negative existentials, sentences of the
form x doesnt exist seem to commit us to the
existence of x and then say of it that it doesnt
existwhich is a contradiction. - Santa Claus doesnt exist
- Unicorns dont exist
6The Source of Our Problems
- We are mislead by language!
- Surface grammar obscures the true logical form
of propositions - Our failure to recognize the true logical form
beneath the surface is responsible for the
puzzles - Subject-predicate form of some sentences is
misleading - Russell proposes an account of the true logical
form of propositions that provides solutions to
the puzzles - He criticizes alternative approaches of Meinong
and Frege - And shows how his account deals with the puzzles
7An Ideal Language
- Disagreement about what philosophy is supposed to
be doing - Analyzing ordinary language or
- Translating into an ideal language that reveals
true logical form - Russell proposes translating ordinary language
into an ideal language that will avoid puzzles
and paradoxes. - The language that reveals logical form and so
allows us to explain validity and to provide
solutions without getting into crazy metaphysics
is . . . - PREDICATE LOGIC WITH IDENTITY!
8Predicate Logic Vocabulary
- Connectives ? , ? , , ? , and ?
- Individual Constants lower case letters of the
alphabet (a, b, c,, u, v, w) - Predicates upper case letters (A, B, C,, X, Y,
Z) - Variables x, y and z
- Quantifiers
- Existential (? variable), e.g. (?x), (?y)
- Universal (variable), e.g. (x), (y)
- Identity (a special predicate)
9Basic Predicate Logic Translation
- Singular propositions
- Russell was a philosopher.Pr
- Russell was Moores friend.Frm
- Russell authored Principia Mathematica with
Whitehead.Arwp - General propositions
- Everything is material(x)Mx
- There is a God.(?x)Gx
10Identity
- Identity is an equivalence relation
- Reflexive everything is identical to itselfx
x - Symmetric if one thing is identical to another
the other is identical to the firstIf x y
then y x - Transitive if one things identical to a second
and the seconds identical to a third then the
first is identical to the thirdIf x y and y
z, then x z - Identity is an indiscernibility relation
- Indiscernibility of Identicals if x y then
whatever is true of x is true of y and vice
versa.
11Ordinary language is deceptive!
- According to Russell, what appear to be simple
singular statements are often really more
complicated existentially quantified statements. - I met a man
- Mm (wrong! a man is not the name of an
individual!) - (?x)Mx (correct translation)
- Even ordinary language statements that include
ordinary proper names are deceptive ordinary
proper names are really disguised descriptions - Apollo lives on Mount Olympus
- (?x)(x is sun god and x is Letos son and
Artemis twin brother andand x lives on Mount
Olympus - Puzzles arise because we think statements that
involve denoting expressions are singular
statements when they are really existential and
generaland involve quantifiers and complicated
logical machinery!
12(No Transcript)
13Denoting
- The subject of denoting is of very great
importance, not only in logic and mathematics,
but also in the theory of knowledge. - No general characterization of denoting is given,
only a list of denoting phrases. - A man
- Some man
- Any man
- Every man
- All men
- The present King of England
- A phrase is denoting solely in virtue of its
form.
14Denoting Phrases and Denotation
- Russell considers three cases
- Denoting phrases that do not denote anything,
e.g. the present King of France in 1905 - Denoting phrases that denote one definite object,
e.g. the present King of England in 1905 - Denoting phrases that denote ambiguously, e.g. a
man - We want an account that will accommodate all
three kinds of cases without paradox - And explain how we can think and talk about many
things with which we are not acquainted but
only know by description.
15Paraphrasing Away Denoting Phrases
- I use C(x) to mean a proposition in which x is
a constituent, where x, the variable, is
essentially and wholly undetermined. - We paraphrase away everything, nothing, and
something as follows - C(everything) means C(x) is always true (x)Cx
- Everything is material for all x, x is material
- C(nothing) means C(x) is is false is always
true (x) ? Cx - Nothing is free for all x, it is not the case
that x is free - C(something) means It is false that C(x) is
false is always true ? (x) ? C(x) i.e. (?x)Cx - Something smells there exists an x such that x
smells.
16More Translations
- I met a man
- I met x and x is human is not always false
(?x)(Mx ? Hx) - All men are mortal
- If x is human then x is mortal is always true
(x)(Hx ? Mx) - No men are perfect
- If x is human then x is perfect is false is
always true (x)(Hx ? ? Px) - Some men are philosophers
- x is human and x is a philosopher is not always
false (?x)(Hx ? Px)
17Definite Descriptions
- The denoting phrase in the sentence The father
of Charles II was executed involves - Existence x was father of Charles II, for some
value of x. - Uniqueness if y was father of Charles II, then y
is identical with x, for any value of x who was
father of Charles II and any value of y. - To convey the uniqueness condition we need to
introduce an additional special predicate, viz
IDENTITY to produce the following translation - There exists an x such that x is the father of
Charles II - For all y, if y is the father of Charles II then
x y - x was executed
18Denoting Phrases All Gone!
- We have now paraphrased away all denoting phrases
- A man
- Some man
- Any man
- Every man
- All men
- The present King of England
- Weve gotten rid of them in favor of logical
machinery--and this will enable us to solve all
three puzzles
19The Identity Puzzle
- Indiscernibility of Identiticals
(substitutivity) If a is identical with beither
may be substituted for the otherwithout altering
the truth or falsity of the proposition - Apparent Counterexample George IV wished to know
whether Scott was the author of Waverly - Scott the author of Waverly
- By substitutivity principle, George IV wished to
know whether Scott was Scott - But George IV did not wish to know whether Scott
was Scott (he knew that!) - So, contrary to the principle we have a case
where substituting a different name for the same
objects makes a true proposition falsewhich is
unacceptable!
20Substitutivity Failures
- There are some contexts in which it looks like we
cannot freely substitute identicals for
identicals - These include intentional contexts which occur in
sentences that ascribe certain mental states,
e.g. - The Minoans didnt believe that the Morning Star
was identical to the Evening Star. - George IV wondered whether Scott was the author
of Waverly. - The Problem everyone knows that everything is
identical with itself BUT - The Minoans believed that the Morning Star was
identical to the Morning Star, but not that the
Morning Star was identical to the Evening Star. - George IV didnt wonder whether Scott was
identical to Scott but did wonder whether Scott
was identical to the author of Waverly.
21Freges Puzzle
- How can true identity statements be informative?
- The Morning Star The Evening Star
- What makes this true is the fact that The
Morning Star and The Evening Star refer to the
same object, viz. the planet Venus so it looks
like the identity statement just says that Venus,
like everything else, is identical to itself! - But everyone knows that everything is identical
to itself so what do we know that the Minoans
didnt know? And what did George IV wonder about?
Surely not whether Scott was identical to
himself! - Russell discusses Freges way of dealing with
this and related issues (pp 4 5) by
distinguishing the meaning and denotation of
denoting expressions well deal with this when
we get to Fregenot now.
22Scope Ambiguity
- Guest I thought your yacht was larger than it
is. - Touchy Yacht Owner No, my yacht is not larger
than it is. - 1 The size I thought your yacht was is greater
than the size your yacht is. - Theres a certain size, x, and I thought that x
was the size of your yacht but x is greater than
the size of your yacht. - 2 I thought the size of your yacht was greater
than the size of your yacht. - I thought that theres a certain size, x which is
the size of your yacht but x is greater than the
size of your yacht. - In 1 the Guest does not believe that the size of
the Owners yacht is greater than it is.
Likewise, in the correct reading George IV
wondered, George IV does not wonder whether
Scott is Scott.
23Russells Solution
- George IV wished to know whether Scott was the
author of Waverly - 1 George IV wished to know whether one and only
one man wrote Waverly and Scott was that man - Secondary occurrence of the author of
WaverlyGeorge IV wished to know whether
(?x)Axw ? (y)(Ayw ? yx) ? xs - 2 One and only one man wrote Waverly and George
IV wished to know whether Scott was that man - Primary occurrence of the author of
Waverly(?x)Axw ? (y)(Ayw ? yx) ? George IV
wished to know whether xs - 1, not 2, is the correct interpretation of the
original sentence. What George IV didnt know but
wanted to know, was whether the proposition
(?x)Axw ? (y)(Ayw ? yx) ? xs was true, and
that is not the same proposition as ss which is
the result of substituting s for x in 2.
24The Excluded Middle Puzzle
- Excluded Middle P or not P
- Consider the sentence P The present king of
France is bald. - P cant be true since there is no present king of
France. - Since its not true it must be false
- Therefore we conclude that the present King of
France is not bald, i.e. not P - But thats also false since there is no present
king of France - But this seems to violate Excluded Middle since
we deny both P and not P
25Russells Solution
- Its false that the present King of France is
bald is ambiguous. - 1 There is an entity which is now king of France
and is not bald.(?x)(Kx Bx) - 2 It is false that there is an entity which is
now king of France and is bald. (?x)(Kx Bx) - Theres a scope ambiguity concerning negation!
- 1is false there is no x who is King of France
and is either bald or non-bald. - 2 is true.
26The Negative Existentials Puzzle
- Negative Existential A claim to the effect that
something doesnt exist, e.g. - Santa Claus doesnt exist
- There are no unicorns.
- Problem the following argument
- 1 If an individual denies the existence of
something, then he refers to what he says does
not exist. - 2 Things which do not exist cannot be referred to
or mentioned no statement can be about them. - 3 Therefore, if an individual denies the
existence of something, then what he says does
not exist exists.
27The Paradox of Non-Being
Parmenides posed the Paradox of Non-Being
28Whats the problem???
- (F) If Ferdinand is not drowned, then Ferdinand
is my only son (p. 3) - Intuitively names dont have sense
(dictionary-meaning) one cannot give a
definition of, e.g. Ferdinand. - So we may say that the meaning of a name is the
object to it denotes, e.g. Ferdinand means that
guy - Therefore, if there is no object a name
denotes,the name is meaningless - And so is any sentence in which it occurs.
- If Ferdinand is drowned, i.e. there is no
objectFerdinand denotes - The sentence (F) is meaningless!
29Whats the solution???
- (F) If Ferdinand is not drowned, then Ferdinand
is my only son (p. 3) - But (F) is not meaningless, so we have a choice
- Meinongs Solution in addition to objects that
exist, there are also possible objects that
subsist and even impossible objects that dont
either subsist or exist. - Russells Solution Ferdinand is not really a
name. - Ferdinand is my only son is not really a
singular, subject-predicate proposition - Neither is The king of France is bald
orUnicorns have one horn. - So lets compare these two solutions
30Meinongs Bloated Ontology
Real things (things that actually exist)
Possibilia (dont actually exist but could they
subsist)
Impossibilia (dont exist, cant exist and dont
even subsist)
Round Squares
Married Bachelors
31Meinongs Solution
- It avoids the flat-out contradiction of having to
say that some things that exist dont exist - Zeus subsists so in saying that Zeus doesnt
exist, were not saying that something that
exists doesnt exist. - But talk about impossible objects, e.g. round
squares, lands us in contradictions. - And we cant/shouldnt arbitrarily analyze talk
about impossible objects differently from talk
about things that exist or subsist. - Furthermore, introducing impossible and merely
possiblethings multiplies objects unnecessarily.
32Russells Solution
- We must abandon the view that denotation is
what is concerned in propositions which contain
denoting phrases. - We have to deal with three kinds of cases,
examplified by - Unicorns dont exist.
- The Fountain of Youth doesnt exist.
- Apollo doesnt exist
- Note in 1 the surface-grammatical subject is a
general term, in 2 its a definite description,
and in 3 its a name
33Solution to Case 1
- Unicorns dont exist.
- It is not the case that there exists an x such
that x is a Unicorn? (?x)(Ux) - __is a unicorn is is a predicate
- We say theres nothing of which that predicate
is true, - i.e. it is not the case that something has the
property of being a unicorn
34Solution to Case 2
- The Fountain of Youth doesnt exist.
- It is not the case that there is one and only
one x thatsthe Fountain of Youth? (?x)Fx ?
(y)(Fy ? y x) - We note that the Fountain of Youth is a
definite description and treat it accordingly. - We say in effect Its false that theres a
unique thing thats a fountain of youth.
35Solution to Case 3
- Apollo doesnt exist
- It is not the case that there is one and only
one x which is C? (?x)Cx ? (y)(Cy ? yx) - C is what the classical dictionary tells us is
meant by Apollo--a description. - Ordinary names are disguised descriptions!
- So Asw isnt strictly speaking (according to
Russells metaphysical account) the correct
translation of Scott was the author of Waverly
since neither Scott nor Waverly are strictly
speaking names. - But well pretend it is to avoid getting into
some heavy metaphysics.
36Genuine proper names
- Russell distinguishes knowledge by acquaintance
and knowledge by description. - Genuine proper names are names of things with
which we are directly acquainted--our current
sense data. - Genuine proper names are simply tags.
- Ordinary names and definite descriptions attach
to objects insofar as the objects have the
characteristics that satisfy the descriptions.
Theyre disguised descriptions
37Russells Theory of Descriptions
- On Denoting was (and by many is) viewed as the
paradigm of analytic philosophy and one of the
greatest pieces of philosophical writing of the
20th century! - It provides the standard analysis of definite
descriptions. - It stood unchallenged for over half a century.
- And then there was Strawson