Frege, Continued

David Sanson

2026-08-26

Announcements

Agenda

  1. Announcements
  2. Review
  3. Work

Reading

  • Reading for next week is Russell, “On Denoting” and Strawson, “On Referring”.
  • Russell’s “Descriptions” is optional, but many find that it is a clearer presentation of some of the key ideas from “On Denoting.”
  • I need to get the “guide” up!
  • I have added a link to these slides to the “guide” for Frege.

Review

Agenda

  1. Announcements
  2. Review
  3. Work

Proper Names, Senses, Referents

  • A proper name is a word or phrase that designates a single determinate thing.
  • Each proper name expresses a sense and refers to a referent.
  • The relation between name and sense is conventional; the relation between sense and referent is not.

Senses

  • A sense is a “mode of presentation” or a “way of thinking about” the referent.
  • Senses are not subjective “conceptions”, but shared objective thoughts: otherwise, communication would be impossible
  • “One can hardly deny that mankind has a common store of thoughts which is transmitted from one generation to another” p. 212
  • To know what a word means is to grasp the sense it expresses.

A Note about ‘Thought’

  • The word thought is subject to an “act-object” ambiguity.
  • Examples: ‘work’, ‘belief’, ‘perception’
  • In each case, there is, on the one hand, the process or act or state—the work, the belief, the perception—and, on the other hand, the product or content—the work, the belief, the perception.
  • Frege is saying that we have access to a shared store of thought contents. He is not saying that we are part of a hive mind that engages in collective acts of thought.

Names express Senses

  • The relation between a name and the sense it expresses is conventional and arbitrary.
  • Two names can express the same sense: synonyms, but also translation.
  • One name should not be used to express more than one sense: ambiguity, which should be avoided.
  • No name should fail to express a sense: nonsense, which should be avoided.

Senses and Referents

  • The sense of a proper name determines a single unique referent—or no referent at all.
  • The relation between a sense and the referent it determines is not conventional.
  • The same referent can be determined by many different senses—there can be many different ways of thinking about the same thing.
  • Some proper names express senses that fail to determine any referent at all: empty names.

Compositionality

  • The meaning of a whole sentence is a function of the meanings of its parts.
  • Compositionality explains your ability to understand sentences you have never heard before:
  • ‘The purple twinkies that you left in the drawer spontaneously combusted.’

Compositionality of Sense and Reference

  • The sense expressed by a whole sentence—the thought it expresses—is a function of the senses expressed by its parts.
  • The referent of a whole sentence—its truth value—is a function of the referents of its parts.

Compositionality and Empty Names

  • If a sentence contains a proper name that fails to express any sense—a nonsense word—that sentence fails to express a thought.
  • If a sentence contains a proper name that expresses a sense, but has no referent, that sentence expresses a thought, but has no truth value.

Work

Agenda

  1. Announcements
  2. Review
  3. Work

Reading

  • Re-read p. 215 and gather your thoughts.
  • Discuss the passage with two people sitting next to you.
  • Can you come up with other examples of sentences with empty names?

Sentences with Empty Names

What does Frege’s view imply about these sentences:

  • ‘Odysseus was set ashore at Ithaca while sound asleep’
  • ‘The largest natural number is even.’
  • ‘The largest natural number is odd.’
  • ‘Sherlock Holmes is a detective.’

Compositionality and Substitutivity

  • The referent—truth value—of a sentence is a function of the referents of its parts.
  • So, if you replace a proper name with another proper name that has the same referent—even if it has a different sense—this should not affect the truth value.

Examples

Argument

  • The largest prime number less than 10 is odd.
  • So, seven is odd.

Argument

  • Superman just flew past my window.
  • So, Clark Kent just flew past my window.

Argument

  • Lois believes that Superman flies.
  • So, Lois believes that Clark Kent flies.

Indirect Speech

Argument

  • Lois believes that Superman flies.
  • So, Lois believes that Clark Kent flies.

Re-read p. 211-212. According to Frege, why is this a bad argument.

Idealism and Skepticism

  • Idealism is the view that there is no external world beyond our ideas.
  • Skepticism is the view that, for all we know, there is no external world beyond our ideas.
  • Both might seem like good reasons to hold, with Locke, that words can only be signs for ideas, not objects in reality.

Re-read p. 214. What is Frege’s take on these issues?

Sentences, Truth Values, and Judgment

  • The view that the referent of a sentence is a truth value is weird!

Re-read p. 215-218.

  • Can we unpack the argument here, that a sentence refers to its truth value, and that the true and the false are objects, not predicates?
  • What is Frege’s account of judgment?

Solving the Puzzle

Re-read p. 230. How does Frege’s theory allow him to solve the original puzzle?