KANT'S A PRIORI
According
to Kant, what knowledge is analytic a priori?
According
to Kant, what knowledge is synthetic a priori?
(1)
All bodies are extended.
(2)
All bodies have weight.
(3)
Gold is a yellow metal.
(4)
7 +5 = 12
(5)
A straight line is the shortest path between two points.
(6)
All substance is permanent (compare: Law
of Conservation of Matter or Law of Conservation of Energy).
(7)
F = ma.
(8)
Every effect has a cause.
(9)
Every event has a cause.
(10)
Principle of Sufficient Reason
(11)
Pure mathematics (includes Euclidean geometry)
(12)
Pure physics (includes
(13)
Law of Excluded Middle
(14)
Law of Non-Contradiction
Kant's
Formula for the Synthetic A Priori: Propositions that must be confirmed by all possible
experience. No experience could
disconfirm them.
Recalcitrant
data from the history of science:
Replacement of Newtonian physics and Euclidean geometry by Relativity
Theory (with a non-Euclidean geometry) and quantum mechanics (with
probabilistic rather than strictly causal relations).
QUINE'S ARGUMENTS AGAINST
ANALYTICITY
(1)
What are the two dogmas?
(2)
Why does Quine think that they are at root the same?
(3)
Why does Quine think that there are no statements
that are confirmed no matter what?
Holistic
confirmation and disconfirmation
Radical revisability.
QUINE'S EXAMPLES
(1) No unmarried man is
married.
(2) No bachelor is
married.
Tests: Interchangeability salva
veritate.
Correct the text (395):
(3) All and only bachelors
are unmarried men
is analytic.
(4) Necessarily all and only
bachelors are bachelors.
(5) Necessarily all and only
bachelors are unmarried men.
Are there any exceptions?
What about the Pope?
Example of "creature
with a heart" and "creature with kidneys"
Is "Everything that is
green is extended" analytic?
BONJOUR'S DEFENSE OF A
PRIORI JUSTIFICATION
I. Two Roles for A
Priori Insight
1.
Source of premises
2.
Validate steps of reasoning.
II. Skepticism about
All A Priori Justification = Intellectual Suicide
Why does BonJour
believe this?
III. Skepticism about
Synthetic A Priori Justification
What is BonJour's
Reply?
IV. BonJour's
Moderate Rationalism
1.
Intuitive apprehension of necessary truth (rational insight or rational
intuition)
2.
Fallibility (apparent rational insight or apparent self-evidence)
3.
An Externalist Requirement: the
condition of cognitive sanity.
V. Examples
1. All bachelors are unmarried.
2. Nothing can be red and green all over at the
same time.
3. Nothing can be red and blue all over at the
same time.
4. If A is taller than B and B is taller than C,
then A is taller than C. (Transitivity
of "taller than")
5. There are no round squares.
6. 2 + 3 = 5 (Compare 2+2 = 4 with 25
– 5 = 33).
7. A cube has 12 edges.
8. Logical example: Inference that David ate the last piece of
cake (105).
9. Law of Non-Contradiction
10. Philosophy is a priori (106).-
BonJour's "Companions in
Guilt" Defense of Synthetic A Priori
Justification
The
Inadequacy of Accounts of Analyticity
(a)
Conditional Accounts
(i) Kantian and Fregean
(ii) also Kant's
alternative formulation
(b)
No Epistemological Insight
(i) Lewis
(ii) Salmon: "empty of factual
content"
(iii) true by
virtue of meaning
(c) Too Obscure or Too Implausible
(i)
true by convention
(ii) implicit
definitions
VI. Issues:
1.
What is the difference between a putative, an apparent, and a rational
insight?
[Why is BonJour
an externalist about both apparent and genuine a priori insight?]
2.
How can a mistaken rational insight be corrected?
[Are all mistakes internally correctable?]
3. Does
reasoning require direct rational insight?
[What is the content of the insight?]
4. Can any
substantive position in philosophy be justified purely a priori—that is,
by direct rational insight of premises and deductive reasoning from such
premises?
[Isn't it relevant whether other people agree or
disagree?]
The Fallibility Problem for
Epistemology and for Philosophy Generally.
Stich's Challenge
Could
human reasoning not be based on a priori insight into valid principles
of inference?
I. The evidence that people do not reason in
accordance with valid principles:
1. Wason Selection Task:
Deductively invalid reasoning.
2.
Inconsistencies in probabilistic reasoning.
3.
Belief perseverance and debriefing.
More
evidence: False Proofs of Fermat's Last
Theorem:
“In 1908, the Wolfskehl
Prize of one hundred thousand marks was offered in
II. Who sets the
standards for Stich?
Experts.
III. How reliable are
the experts? The Monty
Hall Problem.
IV. Could there be an
empirical test for good reasoning?
V. How would BonJour
reply?