Frege and Wittgenstein on Sense, Reference and Thought

1
Frege and Wittgenstein on Sense, Reference and
Thought

• Reading Freges On Sense and Reference and The
  Thought in comparison with Tractatus 3 through
  4.243

2
Senses and References of Names

• In On Sense and Reference, Frege argued that
  names must have senses in addition to references.
  See pages 56 through 58.
• Why didnt Wittgenstein believe that names have
  senses? See T 3.2 through 3.3.
• What does 3.3 mean in Tractatus?

3
More on Senses and References

• On page 60 of On Sense and Reference, Frege
  draws an analogy between ideas, senses and
  references on the one hand and the images
  associated with a reflecting telescope on the
  other. Can you say precisely what that analogy
  is? Are the details of the analogy correct? How
  would Wittgenstein have replied to the analogy?
  See T 3.22 through 3.261.

4
A Skeptical Problem and Its Proposed Solution

• On pages 61 and 62 of On sense and reference,
  Frege takes up a skeptical problem. What is that
  problem?
• How does Frege respond to the problem?
• What, do you think, is the solution that Frege
  here has in mind?
• Is there a similar problem and proposed solution
  in Freges The Thought?

5
Sense and Reference

• On page 62 of On Sense and Reference, Frege
  argues that the thought cannot be the referent of
  a sentence and that the thought expressed by a
  sentence must be its sense.
• What is Freges argument?
• What principles does Frege assume?
• Would Wittgenstein agree with Freges conclusion?
  See T 4.0621.

6
Senses and References

• On page 63, Frege argues that sentences have
  referents. What is his argument for this
  conclusion?
• According to Frege, what are the referents of
  sentences?
• Would Wittgenstein agree with this conclusion?
  See T 3.142 and 3.221.

7
Barwise and Perry, The Slingshot

• This argument is attributed to Frege by Alonzo
  Church. Its conclusion is that, if sentences name
  facts, then all true sentences name the same
  fact.
• Assumptions 1 Logically equivalent sentences
  have the same referents. 2 The referent of a
  sentence is determined compositionally.
• Remember x x 1 and R is a class abstract.

8
The Slingshot Argument

• Let R and S be two true sentences. The following
  listed expressions all have the same referent.
• R
• 1 x x 1 and R By Log. Equiv.
• 1 1 By Compositionality R is true
• 1 x x 1 and S By Compositionality S is
  both true.
• S By Logical Equivalence
• Therefore, R and S refer to the same thing.

9
Wittgenstein and the Slingshot

• How would Wittgenstein respond to the Slingshot
  Argument?

10
Frege on the Correspondence Theory

• On page 291 of The Thought, Frege argued
  against a correspondence theory of truth. What
  was his argument?

11
Freges Arguments for an Outer World

• These arguments appear on pages 301 through 311
  of The Thought.