PhilosophersKurt Gödel

Kurt Gödel

A logician who gave a formal version of the ontological proof.

Platonism1906 · 1978 AustriaBrno

Life

A logician and mathematician born in Brno and died in Princeton, Kurt Gödel proved his incompleteness theorems in 1931: in any consistent formal system rich enough for arithmetic, some true statements remain unprovable. In 1940 he also showed that the continuum hypothesis cannot be refuted from the usual axioms. A Platonist, he held mathematical objects to be real and, around 1970, wrote out a formal version of the ontological proof of God's existence.

Main works

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

Proves that no consistent formal system rich enough for arithmetic can prove all the truths it expresses.

1947
What is Cantor's Continuum Problem?

Defends mathematical realism: sets exist and can be grasped by a kind of intuition.

1995
Ontological Proof

A formal modal-logic version of the argument of Anselm and Leibniz, written around 1970 and published in the Collected Works.

In his own words

« Despite their remoteness from sense experience, we do have something like a perception also of the objects of set theory, as is seen from the fact that the axioms force themselves upon us as being true. »
What is Cantor's Continuum Problem?, supplément de 1964 (Collected Works II, 1990, p. 268)
« A probable decision about its truth is possible also in another way, namely, inductively by studying its "success." Success here means fruitfulness in consequences »
What is Cantor's Continuum Problem? (1947 ; version révisée 1964), Collected Works II (1990)

Positions

click a row to see the evidence
Does God exist?God
AtheismTheism
Stated

He wrote out a formal ontological proof of a God-like being and privately held that God exists.

Gödel, "Ontological Proof" (notes c. 1970, Collected Works III)

Where does knowledge come from?Source of knowledge
Empiricism (from experience)Rationalism (from reason)
Stated

Mathematical objects are real, and we know them by a kind of intellectual perception, not by the senses.

Gödel, "What is Cantor's Continuum Problem?" (1947, rev. 1964)

Can we reach certain truths?Certainty
SkepticismCertainty attainable
Interpretation

Some mathematical truths are reachable with certainty, yet his incompleteness theorems show no fixed formal system can prove them all.

Gödel, "Über formal unentscheidbare Sätze der Principia Mathematica und verwandter Systeme I" (1931)

Is the mind more than matter?Mind and body
MaterialismDualism
Interpretation

He argued the human mind may exceed any machine, which points beyond a purely mechanical view of the mind.

Gödel, Gibbs Lecture "Some basic theorems on the foundations of mathematics and their philosophical implications" (1951)