Peter Forrest expounds a program of best-explanation apologetics. He contends that since the existence of God would provide the best possible explanation of various facts, those facts support theism. Among the facts cited are the suitability of the universe for life, the regularity of the universe, the human capacity for intellectual progress, the experience of a moral order, and various forms of beauty.

The beauty that interests Forrest as evidence for the existence of God includes sensuous beauty; the beauty of the natural order, as revealed by the sciences; and the beauty of necessity discovered by mathematicians.

In addressing the need for an adequate motive for creation, Forrest conjectures that God created the universe for embodied persons not for their life on earth alone but also for an afterlife. Forrest acknowledges the speculative nature of such an account. He suggests that philosophical speculation is also required to defend theism against the charge that it is too extravagant a hypothesis to be warranted.

Providing a speculative defense against the argument from evil, he explains how such speculations can be used to support best-explanation arguments without the conclusions themselves being rendered purely speculative.