The Cosmological Argument (also called the "First Mover" Argument or "First Cause" Argument) is the the most popular argument for God's existence. Cosmological arguments are used by theologians and laymen of all denominations to persuade their own members, and as the primary tool for apologists to use against atheists. Catholic philosophers rely heavily on Cosmological Arguments, since they are utterly convinced by them. St. Thomas Aquinas indirectly created the Cosmological Argument, which is a refined combination of three of the five proofs of God's existence he listed in his magnum opus, Summa Theologica (1274).
In its most general form, the Cosmological Argument states that causality (i.e., the Law of Cause and Effect) dictates that the creation of the universe requires a creator (a "first mover"), which is assumed to be the God of Abraham. As such, the Cosmological Argument is an a priori (before-the-fact) variation of the Teleological Argument. Cosmological Arguments are often used in conjunction with the Argument from Ignorance and the God of the Gaps Argument, since they answer mysteries with more mysteries, and thus answer nothing. The Cosmological Argument is commonly deduced from St. Thomas’ arguments, or restated as the Kalām Argument.
Aquinas made the following arguments for God's existence:
- Motion. Since nothing moves by itself, there must be a "first mover" who set the universe into motion.
- Causality. Every effect can be traced back to some cause, which in turn has its own cause. This causal regression must lead back to a "first cause" which set all events into motion.
- Possibility and Necessity. Everything in existence had previously not-existed at some point. However, if nothing existed, it would not be possible for everything to be brought into existence. Therefore, a creator must necessarily exist in order to create everything.
- All existing things have a beginning and a cause.
- The universe has a beginning.
- Therefore, the universe has a cause.
However, these arguments have their shortcomings, which are listed in order of importance:
- Cosmological Arguments require ad hoc reasoning to avoid infinite regressions. Who moved the first mover? What caused the first cause? If a creator necessarily exists, then who created him? While apologists may claim that God had no cause, or that he was only an effect, but this only highlights the problem -- the Cosmological Argument makes a causal argument based upon the non-existence of causality. If God always existed and needs no causal explanation, then the original premise of the Cosmological Argument -- that everything needs a cause -- is false, since something can and does exist without a cause. If everything except God requires a cause, then the Cosmological Argument becomes ad hoc (i.e., inconsistent and prejudicially applied) and is thus logically impermissible, and unable to advance our understanding of universal causation.
- There is nothing specifically Christian about the Cosmological Argument. The Cosmological Argument offers no clues to the first mover's identity or origin; this could equally refer to any god from any religion, the collaborative effort of several gods, or some not-yet-understood physical phenomena.
- Non-existence is assumed to be the default state. Existence of the universe as a proof of divinity only works under the assumption that non-existence is the default state. What if the universe always existed by default? While apologists will oppose this notion, it is no better, worse, or different than assuming that God also had no cause. If God’s existence can be self-caused, then why can’t the world be self-caused?
- G. H. Smith, Atheism: The Case Against God (Prometheus Books, 2016).
- P. Boghossian, A Manual for Creating Atheists (Pitchstone Publishing, 2013).
- D. Barker, Losing Faith in Faith: From Preacher to Atheist (Freedom from Religion Foundation, 1992).
- D. Mills, Atheist Universe: The Thinking Person's Answer to Christian Fundamentalism (Ulysses Press, 2006).
- D. Barker, Godless: How an Evangelical Preacher Became One of America's Leading Atheists (Ulysses Press, 2008).
- Critiques of God: Making the Case Against the Belief in God, edited by P. A. Angeles (Prometheus Books, 1997).