The authors run through the major arguments for the existence of God: Anselm’s ontological argument (and also Descartes’s version), arguing that the very notion of God a priori proves hs existence; Aquinas’s cosmological (or causal) argument, that God is needed to stop an infinite regression of causes from the present to the past; and the teleological argument or the argument from design, that the design-like natural objects of this world demand a designer. Then they raise the standard objections: Gaunilo’s criticism that the ontological argument proves the existence of perfect islands, which is ridiculous, and Kant’s objection that you cannot infer matters of fact by a priori reasoning; Dawkins’s criticism that the cosmological argument raises the unanswered question of what causes God; and Hume’s criticism of the design argument, and Darwin’s subsequent demonstration that natural selection can explain final causes naturalistically, and so there is no need to invoke a Designer God.