Natural theology is that branch of theology, also known as physicotheology, based on seeking evidence for God in the natural world. It played an important role, especially in the eighteenth and first half of the 19th centuries (prior to the publication of Darwin's Origin of Species), in the debate over pluralism.

Supporters of natural theology maintained that the existence of life and, in particular, intelligent life on other worlds, should be taken as evidence of God's omnipotence and generosity (see teleology). They sought to allay fears from religious traditionalists that pluralism undermined the view that God and man had a special relationship. But although natural theology was successful in persuading many of its case for a God of the universe, it ran into problems in explaining how an incarnated redeemer – Jesus – could act to save souls throughout the cosmos (see incarnation and redemption). Among the principal advocates of natural theology were Johann Bode, David Brewster, Thomas Chalmers, William Derham, William Herschel, Johann Lambert, Johann Schröter, Emanuel Swedenborg, and Thomas Wright. Among those who combined natural theology with an antipluralist viewpoint was William Whewell.