P1: A
sentence S is meaningful only insofar as it pictures reality. (Wittgenstein’s Picture Theory of Meaning)
P2: Our
only access to reality is through the senses and empirical investigation. (Empiricism)
C: So S is meaningful only
if it can be empirically verified.
1.
S
is meaningful iff we can establish that S is true through empirical
investigation.
Counter: “There are mountains on the dark side of
the moon.” (Said before we had technology to go to the moon)
2.
S
is meaningful iff we can in principle establish that S is true through
empirical investigation.
Counter: “All crows are black.”
3.
S
is meaningful iff we can in principle establish that S is false through empirical
investigation.
Counter: “Some crows are not black.”
4.
S
is meaningful iff we can in principle either establish that S is true or
establish that S is false through empirical investigation.
Counter: “Someone loves everyone.”
5.
S
is meaningful iff we can in principle provide support for the truth of S
through empirical investigation.
Problem: Difficult to give precise understanding
of ‘support’
I.
Empiricist Criterion of
Factual Content:
All claims that have factual content/are about reality are subject to the test of sensory experience.
A.
Objection:
Truths of math and logic seem to have factual
content and be logically certain. But
no claim subject to the test of sensory-experience is logically certain.
B.
Reply:
Must either (a) deny that truths of math and logic are logically certain, or (b) deny that they have factual content.
1.
Mill
denies that they are logically certain by claiming that there are empirical
generalizations.
2.
Positivists
deny that they have factual content by claiming that they are analytic
tautologies that are merely about the way we use certain symbols.
C.
Empiricist
Criterion of Significance:
A claim is significant iff it is a claim about the world (and so empirically testable) or
a claim about how we use symbols (and so an analytic tautology).
III.
Logical Status of Criterion
Itself
A.
Objection:
The criterion itself seems to be neither empirically
testable nor an analytic tautology.
B.
Reply:
1.
Convention: The criterion is a prescription for the
notion of significance.
2.
Explication:
The criterion is a precisification of the notion of significance.