Abstract
Contrary to Grunbaum’s BJPS 2000 criticism of my natural theology, there are objective a priori criteria for how far evidence renders a hypothesis probable. These include the simplicity of the hypothesis and how far it makes probable the evidence. Theism is a simple hypothesis and, in virtue of God’s perfect goodness, we have some reason to suppose that he will bring about an orderly world in which there are humans. Hence, the existence of such a world is evidence for the existence of God.