what is not frege’s caesar problem

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What is not Frege’s Caesar Problem? Bruno Bentzen¹ ¹ Department of Philosophy, Graduate Student Federal University of Pernambuco [email protected] What is not Frege’s Caesar Problem? Bruno Bentzen

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Page 1: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem?

Bruno Bentzen¹

¹ Department of Philosophy, Graduate Student

Federal University of Pernambuco

[email protected]

What is not Frege’s Caesar Problem? Bruno Bentzen

Page 2: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 3: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 4: What is not Frege’s Caesar problem

4

• Numbers are value-ranges

• Value-ranges are contextually defined by Basic Law V.

What is not Frege’s Caesar Problem? Bruno Bentzen

Value-ranges?

Page 5: What is not Frege’s Caesar problem

• Define the value-range of f as:

• Do we really know what does this name mean?

Value-ranges?

5 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 6: What is not Frege’s Caesar problem

• Define the value-range of f as:

• Do we really know what does this name mean?

• No we don’t!

Value-ranges?

6 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 7: What is not Frege’s Caesar problem

• Same objects can be denoted by different names

• The value range of f could be also denoted by, say, q

Value-ranges?

7 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 8: What is not Frege’s Caesar problem

• Now ask if eventually is to be the case.

• We have no means to find q’s corresponding function to apply our criteria of identity!

Value-ranges?

8 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 9: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 10: What is not Frege’s Caesar problem

10 What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

• Let Δ be an attribution from objects to “ ” names.

• Let h be a non-trivial permutation of all objects.

Page 11: What is not Frege’s Caesar problem

11 What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

• Let Δ be an attribution from objects to “ ” names.

• Let h be a non-trivial permutation of all objects.

• Consider a very similar attribution Δ’ except that:

• For every object a assigned by Δ to “ ”, Δ’ will assign h(a) instead.

• Thus: Δ’ is a different than Δ, but it is also consistent with BLV if so is Δ.

Page 12: What is not Frege’s Caesar problem

12

Δ attribution:

Basic Law V: True False

What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

Page 13: What is not Frege’s Caesar problem

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Δ’ attribution:

Basic Law V: True False

What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

h( ) h( ) h( ) h( )

Page 14: What is not Frege’s Caesar problem

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Δ’ attribution:

Basic Law V: True False

What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

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Δ attribution:

Basic Law V: True False

What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

Page 16: What is not Frege’s Caesar problem

16 What is not Frege’s Caesar Problem? Bruno Bentzen

Permutation Argument

• The reference of “ ” names is left undetermined by Basic Law V

• How can this be solved?

Page 17: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 18: What is not Frege’s Caesar problem

18 What is not Frege’s Caesar Problem? Bruno Bentzen

Extra Stipulation

• Frege’s theory contains either value ranges names or truth value names

• Indeterminacies could only occur in identity statements between these two names

Page 19: What is not Frege’s Caesar problem

19 What is not Frege’s Caesar Problem? Bruno Bentzen

Extra Stipulation

• Stipulate truth-values to be singletons (then value ranges)

• Then Every object denotable by the names of the theory are value ranges

Page 20: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 21: What is not Frege’s Caesar problem

21 What is not Frege’s Caesar Problem? Bruno Bentzen

Dummett’s View

• What about The Moon, the Sugar Loaf – they are not also objects?

Page 22: What is not Frege’s Caesar problem

22 What is not Frege’s Caesar Problem? Bruno Bentzen

Dummett’s View

• What about The Moon, the Sugar Loaf – they are not also objects?

• Stipulations still leave open whether “Caesar” is a value-range or not (1981).

Page 23: What is not Frege’s Caesar problem

23 What is not Frege’s Caesar Problem? Bruno Bentzen

Dummett’s View

• Can we quantify without “be afraid” of Caesar? (Heck, 1999)

• Take this sentence. Is it true or false?

Page 24: What is not Frege’s Caesar problem

24 What is not Frege’s Caesar Problem? Bruno Bentzen

Dummett’s View

• Can we quantify without “be afraid” of Caesar? (Heck, 1999)

• Take this sentence. Is it true or false?

• Problem is left unsolved!

Page 25: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 26: What is not Frege’s Caesar problem

26 What is not Frege’s Caesar Problem? Bruno Bentzen

Caesar Problem

• Numbers are logical objects

• Logical objects oppose ordinary objects

Page 27: What is not Frege’s Caesar problem

27 What is not Frege’s Caesar Problem? Bruno Bentzen

Caesar Problem

• Definitions have to establish:

• Numbers Ordinary object

Page 28: What is not Frege’s Caesar problem

• Define the number of f as:

• Do we really know what does this name mean?

Caesar Problem

28 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 29: What is not Frege’s Caesar problem

• Define the number of f as:

• Do we really know what does this name mean?

• No we don’t!

Caesar Problem

29 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 30: What is not Frege’s Caesar problem

• Same objects can be denoted by different names

• The number of f could be also denoted by, say, q

Caesar Problem

30 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 31: What is not Frege’s Caesar problem

• Now ask if eventually is to be the case.

• We have no means to find q’s corresponding function to apply our criteria of identity!

Caesar Problem

31 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 32: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 33: What is not Frege’s Caesar problem

• Dummett’s View:

Splitting the problems

33 What is not Frege’s Caesar Problem? Bruno Bentzen

Value-ranges problem

Caesar Problem

Page 34: What is not Frege’s Caesar problem

• Dummett’s View: The objective of this paper

Splitting the problems

34 What is not Frege’s Caesar Problem? Bruno Bentzen

Value-ranges problem

Caesar Problem

Page 35: What is not Frege’s Caesar problem

• Concerning value-ranges, the problem is technical

• Caesar Problem is philosophical

Splitting the problems

35 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 36: What is not Frege’s Caesar problem

• Concerning value-ranges, the problem is technical – semantic

• Caesar Problem is philosophical – metaphysical

Splitting the problems

36 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 37: What is not Frege’s Caesar problem

Proposition:

Splitting the problems

37 What is not Frege’s Caesar Problem? Bruno Bentzen

• Concerning value-ranges, the problem is solvable

• Caesar Problem keeps unsolvable

Page 38: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 39: What is not Frege’s Caesar problem

• Against Dummett there’s no (semantical) problem regarding value-ranges.

• Caesar could only appear as a problem in quantified sentences

• Frege’s criteria of referentiality of quantified sentences is substitutional

Solving value-ranges problem

39 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 40: What is not Frege’s Caesar problem

• “To investigate whether the name “ ” of a second-level function denotes something, we ask whether it follows universally from the fact that the function-name “ ” denotes something, that “ ” succeeds in denoting. Now “ ” has a denotation if, for every denoting proper name “a”,

“ F(x) ” denotes something. If this is the case, then this denotation either always is the True (whatever “a” denotes), or not always. In the first case ” “ denotes the True, in the second the False.”

Basic Laws of Arithmetic, §31)

Solving value-ranges problem

40 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 41: What is not Frege’s Caesar problem

• Whether ordinary objects are or not in the domain is irrelevant to fix the meaning of

• What is at stake is what names there are!

Solving value-ranges problem

41 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 42: What is not Frege’s Caesar problem

What is not Frege’s Caesar Problem? Bruno Bentzen

Summary

• Value-ranges?

• Permutation Argument

• Extra Stipulation

• Dummett’s View

• Caesar Problem

• Splitting the problems

• Solving value-ranges problem

• Caesar Persists!

Reconstructive part

Argumentative part

Page 43: What is not Frege’s Caesar problem

• We can’t ask anymore whether Caesar is a value range or not in the theory!

• Is Caesar Problem then solved?

Caesar Persists!

43 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 44: What is not Frege’s Caesar problem

• We can’t ask anymore whether Caesar is a value range or not in the theory!

• Is Caesar Problem then solved?

• No!

Caesar Persists!

44 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 45: What is not Frege’s Caesar problem

• We still have a metalinguistic problem (Dummett, 1981):

• is “the referent of ‘ ’ is Julius Caesar” True or False?

Caesar Persists!

45 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 46: What is not Frege’s Caesar problem

• To establish that extensions are uncontroversially logical objects then they could never be ordinary objects in advance would be to beg the question!

Caesar Persists!

46 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 47: What is not Frege’s Caesar problem

• To establish that extensions are uncontroversially logical objects then they could never be ordinary objects in advance would be to beg the question!

Thank you for your attention!

Caesar Persists!

47 What is not Frege’s Caesar Problem? Bruno Bentzen

Page 48: What is not Frege’s Caesar problem

• Frege, G. (1987). Die Grundlagen der Arithmetik: Eine logisch mathematische Untersuchung über den Begriff der Zahl. Stuttgard: Philipp Reclam

• ______. (1998). Die Grundgesetze der Arithmetik I/II. Georg Olms: Hildesheim

• Dummett, M. (1981). Frege: Philosophy of Language. U.K: Duckworth

• Heck, R. (1999). Grundgesetze der Arithmetic I §10. Philosophia Mathematica, v. 7, n. 3, p. 258-292, out

• Ruffino, M. (2002). Logical Objects in Frege’s Grundgesetze, Section 10. In: Reck (Ed.). From Frege to Wittgenstein, Oxford: Oxford University Press. p. 125-48

References

48 What is not Frege’s Caesar Problem? Bruno Bentzen