Book excerpt: This volume explores the philosophical issues involved in the idea of petitionary prayer, where this is conceived as an activity designed to influence the action of the all-knowing, all-powerful, perfectly good God of traditional theism. Theists have always recognized various logical and moral limits to divine action in the world, but do these limits leave any space among God's reasons for petitionary prayer to make a difference? Petitionary Prayer: A Philosophical Investigation develops a new account of the conditions required for a petitionary prayer to be answered by employing the notion of contrastive explanation. With careful attention to recent developments in metaphysics, epistemology, and value theory, Scott A. Davison surveys the contemporary literature on this question. He considers questions about human freedom and responsibility in relation to different views of divine providence, along with the puzzles inherent in Christian teachings concerning petitionary prayer. Davison develops new challenges to the coherence of the idea of answered petitionary prayer based upon the nature of divine freedom, the limits of human knowledge, and the nature of those good things that require a recipient's permission before they can be given. He proposes new defenses, building upon careful analysis of the shortcomings of previous proposals and clarifying the issues for future debate.