Sam Harris on The Kalam cosmological argument

Harris has addressed the Kalam cosmological argument in several debates and discussions, most notably in his exchanges with William Lane Craig. His primary objection is to the conceptual analysis that follows the formal argument. Even granting both premises — that everything beginning to exist has a cause, and that the universe began to exist — the conclusion is merely that the universe has a cause. The leap from 'cause of the universe' to 'personal, timeless, spaceless, immaterial creator who is also the God of Christianity' involves a series of inferences that Harris finds completely unjustified.

He also questions whether the concept of causation applies to the origin of the universe. Our experience of cause and effect occurs within spacetime. The beginning of the universe — if it had one — is the beginning of spacetime itself. Asking what caused spacetime may be as incoherent as asking what is north of the North Pole. The Kalam assumes that the universe's origin must resemble the origin of everyday objects, but this assumption has no empirical support.

Harris has noted in his debates with Craig that the Kalam, even if sound, does nothing to establish the truth of Christianity specifically. Craig uses it as the first step in a cumulative case, but Harris regards each subsequent step — from first cause to personal God to Christian God — as involving ever-larger inferential leaps with ever-less justification.