The Cosmological Argument

The Cosmological Argument is one of the oldest and most influential arguments for the existence of God. Unlike the design argument, which reasons from the apparent order of the universe, the cosmological argument reasons from the sheer existence of the universe. It asks a deceptively simple question: why is there something rather than nothing? The argument contends that the existence of the universe requires an explanation, and that this explanation must ultimately be found in a necessary, self-existent being — God. This lesson examines the major formulations, from Aquinas to the Kalam argument, the key criticisms, and the philosophical debate about whether the universe demands an external cause.

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Aquinas' Three Ways

St Thomas Aquinas (1225–1274) presented three versions of the cosmological argument in his Summa Theologica (the first three of his Five Ways). Each approaches the question of God's existence from a different angle, but all share the same logical structure: they begin with an observable feature of the world and argue that this feature requires an ultimate explanation that terminates in God.

The First Way: The Argument from Motion (Change)