Logical Positivists believed that all traditional philosophical problems are pseudo problems

According to them, all of these questions were literally meaningless.

They were meaningless because they were not, in principle, verifiable.

Logical Positivist centered around

  • Vienna Circle (Schlick, Carnap, ...)
  • Berlin Circle (Reichenbach, ...)

 

 

 

1. Wittgenstein

  • Influenced the Logical Positivism, especially the Vienna Circle
  • Argued philosophical disagreements and confusions can be resolved by analyzing the use and abuse of language

Tractatus Logico-Philosophicus

  • He wrote this book during WWI as a POW
  • Presented Picture Theory of Meaning, supposed to show that all philosophical problems are meaningless

 

 

 

2. Ayer

Language, Truth, and Logic

Informal Idea: There is no truth except scientific truth

  • Try to draw a boundary between meaningful sentences (science) and others

  • Metaphysics claims are meaningless

    Examples

    1. Are the past/future real?
    2. Do numbers, properties, and abstract objects exist?
    3. Does god exist?

    These claims are meaningless

  • Differences between science and others

    science is empirical, it involves sensory experience

    scientist are entertaining claims that are verifiable by sensory experience

 

 

 

3. Verification Principle

  • Principle 1 - A sentence is meaningful if and only if it if verifiable (Schlick)

    Hurdle: Explaining facts about ethics, aesthetics, and math

    • Ethics & Aesthetics

      • Schlick - Ethical & Aesthetical statements are verifiable

        Nowadays, this position is known as "Naturalism" about metaethics

      • Carnap - Ethical & Aesthetical statements are commands

        Nowadays, this position is known as “Imperativism” about metaethics

      • Ayer - Ethical & Aesthetical statements are emotive outbursts

        Nowadays, this position is known as “Emotivism” about metaethics

    • Math

      • Schlick - Mathematical statements are verifiable

      • Mill - Mathematical statements are empirical

      • Ayer - Mathematical statements are analytically true

        if you analyze "", it would look like "If it is raining, then it is raining"

      They seem concerned that mathematical statements are meaningless, so they pivoted to Principle 2

 

  • Principle 2 - A sentence is meaningful if and only if it if verifiable or analytically true

    Examples

    • All bachelors are unmarried

    Ayer - Mathematical statements record one's commitment to a linguistic convention

    Evidence

    If someone said, "", we would say that he is using one of the terms in the sentence incorrectly

    When math seems to give rise to new knowledge, it is really just revealing our prior commitments

 

  • Principle 3 - A sentence is meaningful if and only if it if verifiable, refutable, or analytically true

 

  • Problems

    "Every raven is black"

    • Not verifiable but refutable
    • Maybe meaningful under Principle 3
    • Counterexample of Principle 2

    "There is a tallest raven"

    • Can be refuted for each
    • Cannot refute the whole claim
    • Counterexample of Principle 3

 

 

 

4. The End of Logical Positivism

There was never a consensus about what a sound verification principle would look like. As such, the logical positivists largely moved on from the project, and considered it debunked