Doctrines concerning God that are allegedly attainable by natural processes of reasoning, as opposed to those that require the assistance of revelation. Atheists and agnostics deny that there are such doctrines, as do some Protestant theologians who emphasize the limitations of fallen human faculties, stressing instead the special need for divine grace. Hume’s Dialogues Concerning Natural Religion is the classical sceptical attack on the arguments of natural theology. See also deism.