THE MEANING OF TRUTH - PowerPoint PPT Presentation

1 / 50
About This Presentation
Title:

THE MEANING OF TRUTH

Description:

it stratifies the truth-concept (treated not as one concept, but many) ... specifically, how truths in science differ from truths in history, in law, & in literature ... – PowerPoint PPT presentation

Number of Views:271
Avg rating:3.0/5.0
Slides: 51
Provided by: sha1170
Category:

less

Transcript and Presenter's Notes

Title: THE MEANING OF TRUTH


1
THE MEANING OF TRUTH
  • SUSAN HAACK
  • ltshaack_at_law.miami.edugt

2
True is a word we all understand, but if we
try to explain it, we can easily get involved in
a maze of confusion. Frank Ramsey
3
  • CORRESPONDENCE THEORIES
  • THE SEMANTIC THEORY
  • THE LACONICIST THEORY
  • CONSEQUENCES OF LACONICISM

4
1. Correspondence Theories
  • some correspondence theories are toothless,
    saying no more than it is true that p if and
    only if really, in fact, p
  • more serious correspondence theories turn those
    emphatic adverbs into serious metaphysics/philosop
    hy of language giving them real bite

5
for example
the Logical Atomist correspondence theories of
Wittgenstein and Russell
6
these require
  • heavy metaphysical apparatus of facts (atomic
    molecular, positive negative)
  • propositions with a specific logical form
  • a relation of structural isomorphism (which
    proved very difficult to spell out)

7
then there was
J. L. Austins version, with correspondence as a
coincidence of demonstrative and descriptive
conventions but this applies only to indexical
statements
8
many still find correspondence attractive
  • but it has (I believe) never been spelled out in
    a way
  • that gets beyond the toothless correspondence
    idea, and
  • doesnt lead to excessive metaphysical
    commitments, or restricted applicability

9
2. The Semantic Theory
has been enormously influential, thanks in part
to the support of Popper, Quine, and Davidson
but not always well-understood
Alfred Tarski
10
Tarski proposes
  • Formal Adequacy Conditions
  • the definition must not be circular
  • should not use semantic primitives
  • can be given only for a language that is formally
    specifiable
  • semantically open

11
the last formal requirement
  • is imposed to avoid the Liar Paradox
  • This sentence is false
  • by requiring truth-in-O (the object language) to
    be defined in a meta-language

12
  • because of the Formal Adequacy conditions, Tarski
    can define truth only for syntactically
    characterizable formal languages
  • can define only true-in-L, not true

13
more famous is
  • Tarskis Material Adequacy Condition
  • any acceptable definition of truth must have as
    consequence all instances of
  • (T) S is true iff p
  • (where S is the name of the sentence on the
    right)

14
the Material Adequacy Condition
  • is not a definition of truth (but a condition on
    acceptable definitions)
  • (according to Tarski) cannot simply be
    generalized
  • so his definition takes an indirect route

15
Tarski defines
  • satisfaction of atomic open formulae (a relation
    to infinite sequences of objects) --
    enumeratively
  • then satisfaction of molecular open sentences --
    recursively
  • then truth of closed sentences satisfied by
    all infinite sequences

16
misunderstandings
  • this is not, as Popper suggests, a version of the
    correspondence theory Tarski wants to
    articulate Aristotles Insight WITHOUT relying on
    correspondence or facts
  • nor is it a disquotationalist theory, as Quine
    suggests if it were, Tarski could simply drop
    his last 100 pages!

17
for, according to Tarski
  • the quotation-mark name of an expression is a new
    word, of which the contained expression is not
    semantically a part
  • you cant quantify into quotation marks
  • (p) (p is true iff p) makes no sense the
    T-schema cant be generalized in this way

18
ironically enough
  • this is the logical block view of quotation --
    which Quine himself once accepted!
  • when he wrote that a word in quotation marks is
    not semantically a part of the whole expression
    any more than rat is of Socrates

19
moreover
  • Tarskis is not, as Soames suggests, a theory of
    the truth of propositions
  • propositions dont have syntactic structure (the
    same proposition can be expressed by sentences
    with different structures)
  • but Ts definition relies on structure of wffs

20
Tarskis approach has real limitations
  • it stratifies the truth-concept (treated not as
    one concept, but many)
  • its application is limited to formally
    specifiable semantically open languages
  • which is why Tarski says truth cannot be defined
    for natural languages

21
Tarski himself is ambivalent
  • he says he doesnt claim to have captured the
    real meaning of true he would be willing to
    use the word frue instead!
  • and yet goes on to say BOTH that he doesnt say
    the semantic theory is right, AND that he cant
    imagine what it would mean to say it is wrong
    (!!!)

22
furthermore
the failure of the Davidson Program confirms
that Tarski was right in thinking his methods
apply to formal, but not natural, languages
Donald Davidson
23
not to mention the failure of Poppers theory
of verisimilitude, or the casualness of his
assumption that Tarskis theory applies to the
consistent parts of natural language
Sir Karl Popper
24
I am inclined to conclude
  • that Tarskis work, though a very impressive
    technical achievement
  • is not, in the end, fully satisfying
    philosophically

25
3. The Laconicist Theory
  • laconicist is a better name for what is usually
    called the Redundancy Theory
  • A belief is true if it is a belief that p, and
    p. . A belief that Smith is either a liar or a
    fool is true if Smith is either a liar or a fool,
    and not otherwise. Frank Ramsey

26
Ramsey is well aware
  • that while it is true that can be eliminated
    from (is redundant in), e.g., It is true that
    Hannibal crossed the Alps
  • it cannot be eliminated form, e.g., Plato said
    some true things and some false things

27
the new name
  • coined by Dr. Kiriake Xerohemona
  • derives from the English word laconic, which
    means short, terse
  • itself derives from the Greek word Laconia,
    the name for the ancient city-state, Sparta

28
to call something spartan (in English) means
that it is austere, simple
29
  • laconicism seems to capture the core meaning of
    true
  • to conform precisely to the Aristotelian Insight

30
still, as Ramsey is aware
  • the theory is incomplete, requiring
  • an account of propositional quantifiers (which
    may not itself use the concept of truth)
  • to explain, e.g. Plato said some true things
    -- (Ep) (Plato said that p, and p)

31
  • an account of representation
  • an understanding of reality
  • which Ramsey takes to be involved in saying that
    this is the belief that p representation, and p
    reality

32
on propositional quantifiers
  • neither an objectual nor a substitutional account
    will do
  • because both involve the concept of truth,
    explicitly or implicitly
  • the inference-ticket approach (suggested by
    Arthur Prior, C. J. F. Williams, María-José
    Frápolli) might work

33
on reality
  • laconicism is entirely compatible with my
    Innocent Realism (itself fairly laconic!)
  • according to which there is one real world
  • largely but not wholly independent of us

34
  • a real world that includes
  • natural things, events, etc.
  • human artifacts
  • social institutions, roles, and rules
  • mental states, processes, events
  • imaginative creations such as novels, plays,
    cartoons, etc.

35
4. Consequences of Laconicism
  • that when we say that it is true that p, what we
    say about p is the same, whatever kind of
    proposition p is (scientific, historical,
    literary, legal, etc.)
  • this is one way to put what I mean by speaking of
    the unity of truth

36
  • that truth is objective
  • i.e. (normally), whether or not it is true that p
    does not depend on whether you, or I, or anyone
    believes it is true that p
  • or on whether we agree that p, or know that p,
    etc.

37
  • that truth is not relative
  • for (just as there is no reference in the account
    of truth to what anyone believes, etc.), there is
    no relativization to culture, community, theory,
    or even (as in Tarski) language

38
moreover
  • laconicism suggests a plausible understanding of
    observations like
  • a genuine inquirer seeks the truth
  • a scientific theory is successful (in prediction,
    technology) because it is true

39
a genuine inquirer seeks the truth
  • means, not that there is a kind of Holy Grail,The
    Truth, that every genuine inquirer seeks
  • but that someone who is genuinely inquiring into
    whether p wants to end up believing that p if p,
    that not-p if not-p

40
e.g.
  • James Watson really wanted to discover the truth
    about the structure of DNA
  • means Watson wanted to end his investigation
    believing that DNA is a double-helical,
    backbone-out macromolecule with like-with-unlike
    base pairs iff DNA is a double-helical, ...,
    macromolecule (etc.)

41
as, of course, it is, and he did!
42
Watson (L) Crick (R) with their model of DNA,
1952 a model Watson described as too pretty
not to be true.
43
again
  • this scientific theory works because it is true
  • means this theory works because it says that p
    and (in fact!) p

44
for example
  • why does the plane not burst at the seams?
  • because it is built using the assumption that
    metal m can withstand pressure p, and this
    assumption is true
  • i.e. because m can withstand pressure p

45
furthermore
  • laconicism can readily explain why true plays
    the pragmatic roles it does
  • e.g., the use of thats true to express
    agreement is just a short way to say yourself
    what the other person just said

46
Rorty suggests he is following Ramsey
  • when he identifies truth with here-and-now
    agreement
  • but this is a big muddle

47
  • thats true often has the force of I agree
  • but (of course) we can agree that p when p is
    not true
  • (of course) we may not agree that p when p is
    true
  • so it is true that p doesnt mean we agree
    that p

48
  • laconicism can also explain the concessive use of
    true
  • A says The price of gold will probably rise B
    replies True, but later it will fall
  • yes, the price of gold will probably rise, but
    after that it will fall

49
next time, I will explore
  • the many different kinds of true proposition (the
    plurality of truths)
  • specifically, how truths in science differ from
    truths in history, in law, in literature

50
but for now, Id like to hear what you think
Write a Comment
User Comments (0)
About PowerShow.com