Philosopher

Rudolf Carnap

1891–1970

Leading figure of logical empiricism and a founder of the philosophy of science, who saw philosophy as the engineering of clearer languages and rejected metaphysics as empty.

In logic, there are no morals.

The Logical Syntax of Language § 17, translation as quoted by Hannes Leitgeb and André Carus

Carnap was born in 1891 in Ronsdorf, now part of Wuppertal in western Germany, and studied philosophy, physics and mathematics at Jena, where Gottlob Frege taught him logic. In the mid-1920s he went to Vienna and joined Moritz Schlick’s circle, which was then reading Wittgenstein’s Tractatus and would soon be known as the Vienna Circle, the source of what came to be called logical positivism, a name Carnap never liked.

He moved to Prague in 1931, where he wrote The Logical Syntax of Language, and as war approached he left Europe for the University of Chicago in 1936, later teaching at UCLA. As logical empiricism fell from favour in the 1950s and 1960s his standing declined, though much of the next generation’s work, Quine’s included, can be read as a response to him. He died in 1970, and since the 1980s his ideas have enjoyed a major revival.

Key ideas

Philosophy as conceptual engineering
Traditional philosophical problems arise largely from the inadequate languages we inherited for everyday, pre-scientific life. Philosophy should build better, more precise concepts and frameworks, replacing vague notions with explicit reconstructions.
Tolerance
There is no single correct language or logic. Everyone may build a linguistic framework as they wish, judged by how well it serves its purposes: “in logic, there are no morals”.
The elimination of metaphysics
Statements that convey nothing, but only purport to say something significant, are “metaphysics”. Carnap spent his life trying to state precisely the difference between such empty verbiage and statements with genuine content.
Confirmation, not verification
Scientific theories range over endless instances, so they can never strictly be verified, only confirmed to some degree. Carnap later developed an inductive logic to measure how far evidence confirms a hypothesis.
The logical construction of the world
In the Aufbau, influenced by his teacher Frege, Carnap tried to bring all the concepts of knowledge into a single system built up from logic and experience.
Tradition
Western
Region
Germany, Austria and United States

Influences

Where these links come from
  • Rudolf Carnap drew on and argued against Immanuel Kant. Source: Hannes Leitgeb and André Carus, Rudolf Carnap, Stanford Encyclopedia of Philosophy
  • Rudolf Carnap studied with and drew on Gottlob Frege. Source: Hannes Leitgeb and André Carus, Rudolf Carnap, Stanford Encyclopedia of Philosophy
  • Rudolf Carnap drew on Ludwig Wittgenstein. Source: Hannes Leitgeb and André Carus, Rudolf Carnap, Stanford Encyclopedia of Philosophy
  • W. V. O. Quine drew on and argued against Rudolf Carnap. Source: Peter Hylton and Gary Kemp, Willard Van Orman Quine, Stanford Encyclopedia of Philosophy

Key works

  • The Logical Structure of the World (Der logische Aufbau der Welt), 1928
  • The Logical Syntax of Language (Logische Syntax der Sprache), 1934
  • Logical Foundations of Probability, 1950
  • Empiricism, Semantics, and Ontology, 1950

Sources

  1. Hannes Leitgeb and André Carus, Rudolf Carnap, Stanford Encyclopedia of Philosophy
  2. Richard Creath, Logical Empiricism, Stanford Encyclopedia of Philosophy