Kurt Gödel

Mathematics Austrian-American 1906 – 1978 527 quotes

Proved incompleteness theorems transforming mathematical logic

Most quoted

"Any consistent formal system F within which a certain amount of elementary arithmetic can be carried out is incomplete; i.e., there are statements of the language of F which can neither be proved nor disproved in F."

— from On Formally Undecidable Propositions of Principia Mathematica and Related Systems, 1931

"Either mathematics is incompletable in this sense, that its evident axioms can never be exhausted by a finite number of formal rules, or else there exist mathematical problems which are undecidable in principle."

— from On Formally Undecidable Propositions of Principia Mathematica and Related Systems I, 1931

"The incompleteness theorems are a profound statement about the limits of formal systems and the indispensable role of human intuition and insight in mathematics."

— from On Formally Undecidable Propositions of Principia Mathematica and Related Systems I, 1931

All quotes by Kurt Gödel (527)

The incompleteness results apply to all sufficiently powerful systems.

Paper 1931

I have proved that Principia Mathematica is incomplete.

Letter to Carnap 1931

Mathematics deals with idealities.

Philosophical note

The axiom of choice is consistent with ZF.

Proof paper 1938

Reason cannot prove its own consistency.

Incompleteness theorem 1931

The mind's ability to see truth beyond formalism is profound.

Essay 1951

Gödel's theorem reveals the gap between truth and provability.

Reflection

Formal systems are limited tools.

Paper 1931

I am interested in the foundations of mathematics.

Early letter 1929

The infinite is the realm where mathematics truly shines.

Continuum hypothesis paper 1940

Belief in God is rational.

Ontological argument 1970

Time is relative, but truth is absolute.

Conversation with Einstein

The second theorem shows that consistency proofs require stronger systems.

Paper 1931

Mathematics is the science of the infinite.

Lecture

I distrust formal systems after my discovery.

Letter 1931

The world is mathematical.

Philosophical view

Provability is not the same as truth.

Incompleteness 1931

Human reason has limits, but truth does not.

Reflection

The diagonal argument is key to undecidability.

Paper 1931

I prefer philosophy to pure mathematics now.

Interview 1940