The Cosmological Argument

The family of a posteriori arguments that infer the existence of a first cause or necessary being from the existence, contingency, or temporal origin of the universe.

Definition

An argument that the existence or contingency of the cosmos requires explanation by a being whose existence is necessary or uncaused, traditionally identified with God.

Scope

This topic covers the principal versions of the cosmological argument: the kalam argument from a temporal beginning of the universe, Aquinas's arguments from motion and efficient causation, and the Leibnizian argument from contingency and the principle of sufficient reason. It covers the standard objections concerning infinite regress, the causal principle, and the inference to a personal God. It does not cover the design argument, treated separately.

Core questions

• Must everything that exists or begins to exist have a cause?
• Can an actual infinite regress of causes be completed, or must the series terminate in a first member?
• Does the contingency of the universe demand a necessary being via the principle of sufficient reason?
• Even if a first cause exists, does it follow that it is the God of theism?

Key theories

Kalam cosmological argument

Craig defends the argument that whatever begins to exist has a cause, that the universe began to exist, and therefore that the universe has a cause, which he argues must be a timeless, changeless, personal agent.

Argument from contingency

On the Leibnizian version, every contingent fact requires a sufficient reason; the totality of contingent things is itself contingent, so its explanation must lie in a necessary being whose existence is self-explanatory.

History

Versions appear in Aristotle's unmoved mover and were developed within medieval Islamic kalam theology, notably by Al-Ghazali, before entering Christian thought through Aquinas's first three Ways. Leibniz and Clarke gave it a rationalist form via the principle of sufficient reason; Hume and Kant criticized it, and Craig revived the kalam version in the late twentieth century.

Debates

Whether an actual infinite is possible

Defenders of the kalam argument hold that an actually infinite past is metaphysically impossible, forcing a beginning; opponents argue that set theory and modern cosmology leave the possibility open.

Whether the principle of sufficient reason is true

The contingency argument depends on every fact having an explanation; critics object that the principle is unproven and that the universe may be a brute fact, while defenders treat it as a foundational rational commitment.

Key figures

• Thomas Aquinas
• Gottfried Wilhelm Leibniz
• Al-Ghazali
• Samuel Clarke
• William Lane Craig
• William Rowe

Seminal works

• rowe1975
• craig1979
• swinburne2004

Frequently asked questions

What is the difference between the kalam and contingency versions?

The kalam version argues from a temporal beginning of the universe to a first cause, whereas the contingency version argues, regardless of whether the universe had a beginning, from the need to explain why anything contingent exists at all.

Does the argument prove the God of a particular religion?

No. At most it concludes to a first cause or necessary being; further argument is needed to identify that being with the personal, omnipotent God of any specific tradition, which critics regard as the weakest step.