(Kurt Gödel (1995). "Ontological Proof". Collected Works: Unpublished Essays & Lectures, Volume III. pp. 403–404. Oxford University Press.
Based on this far-reaching rational belief, he thought he can prove the existence of God, in a modified (and logically consistent) version of Anselm's ontological proof. The argument, reproduced below, needs more explanation. Gödel was a theist, not a pantheist, and he also rejected Einstein's idea of an impersonal God. He saw himself in the tradition of Leibniz, not Spinoza. Gödel worked on the "ontological proof" for a long time, and finally, he handed it over to a friend in 1970. It was published in 1987.
Translated into English:
Assumption 1: No property in collection P will be the inverse of another property also in P.
Assumption 2: If a property is in P, and if for all objects with that property that implies the existence of some other property in every possible situation, then the collection P also contains the other property.
Theorem 1: If a property is in P, an object might exist with that property.
Definition 1: An object has the “God-like” property if, and only if, that object has every property in P.
Assumption 3: The “God-like” property is in P.
Theorem 2: At least one object might have the “God-like” property.
Definition 2: A property is an “essential property” of an object if, and only if, every property that object has must be implied by the essential property, in every possible situation.
Assumption 4: Any property in P must be within P in every situation.
Theorem 3: If an object has the “God-like” property, that property must be an essential property.
Definition 3: An object has the “Anselmian God” property if, and only if, all its essential properties imply that, in every possible situation, an object exists with that essential property.
Assumption 5: The “Anselmian God” property is in P.
Theorem 4: There must exist an object with the “God-like” property in every situation.
He left in his papers a fourteen-point outline of his philosophical beliefs, that are dated around 1960. They show his deep belief in the rational structure of the world. ( Wang, Hao. A Logical Journey: From Gödel to Philosophy. A Bradford Book, 1997. Print. p.316.)
Here are his 14 points:
The world is rational.
Human reason can, in principle, be developed more highly (through certain techniques).
There are systematic methods for the solution of all problems (also art, etc.).
There are other worlds and rational beings of a different and higher kind.
The world in which we live is not the only one in which we shall live or have lived.
There is incomparably more knowable a priori than is currently known.
The development of human thought since the Renaissance is thoroughly intelligible (durchaus einsichtig).
Reason in mankind will be developed in every direction.
Formal rights comprise a real science.
Materialism is false.
The higher beings are connected to the others by analogy, not by composition.
Concepts have an objective existence.
There is a scientific (exact) philosophy and theology, which deals with concepts of the highest abstractness; and this is also most highly fruitful for science.
Religions are, for the most part, bad-- but religion is not.