Kalam Cosmological Argument

Premise 1: Whatever begins to exist has a cause

Craig argues that it is intuitively obvious and metaphysically necessary that anything that begins to exist must have a cause. This principle is grounded in the observation that nothing comes into being without a cause in our experience.

Premise 2: The universe began to exist.

Craig supports this premise with both philosophical and scientific arguments. Philosophically, he contends that an infinite regress of events is impossible, as an actual infinite cannot exist in reality (e.g., Hilbert’s Hotel paradox). Scientifically, he points to evidence like the Big Bang theory, which suggests the universe had a definite beginning in time.

Conclusion: Therefore, the universe has a cause.

From the first two premises, it follows logically that the universe must have a cause. Craig further argues that this cause must be timeless, spaceless, powerful, and personal, as it must transcend the universe and have the ability to initiate the universe’s existence. He identifies this cause with God.

Objection: What caused God?

The Kalam argument posits that everything that begins to exist has a cause. God, as conceived in the argument, is a timeless, eternal, and uncaused being who did not begin to exist. Therefore, God does not require a cause, as the principle of causality only applies to things that have a beginning. Craig argues that God, as the transcendent cause of the universe, exists outside of time and space, making the question of “what caused God?” inapplicable, as it misunderstands God’s nature as an uncaused, necessary being.

Hilbert Hotel paradox

Hilbert’s paradox of the Grand Hotel illustrates the counterintuitive nature of infinite sets. Imagine a hotel with infinitely many rooms (numbered 1, 2, 3, …), all fully occupied. When a new guest arrives, the manager accommodates them by asking each current guest in room n to move to room n+1, freeing up room 1—showing that infinity plus one is still infinity.

The paradox deepens: Even if infinitely many new guests arrive (e.g., one busload), they can be housed by shifting existing guests to even-numbered rooms (2, 4, 6, …), leaving all odd-numbered rooms (1, 3, 5, …) for the newcomers. For countably infinite buses of infinite guests each, a bijection (one-to-one correspondence) using natural numbers or primes demonstrates that the cardinalities match, revealing how infinite sets defy finite intuition: |\mathbb{N}| + |\mathbb{N}| = |\mathbb{N}|.