The transcendental argument for God's existence takes different forms, but is basically an argument based upon the necessary preconditions for transcendentals. Transcendentals are those things which are true but do not depend on material conditions such as location and time for their validity. Such transcendentals include the laws of logic: the law of identity, the law of non-contradiction, the law of excluded middle, and the law of proper inference. These are not dependent on space, time, or humans for their validity.
See the article The Transcendental Argument for the Existence of God.