Evolutionary biologist Richard Dawkins criticizes all faith by generalizing from specific faith in propositions that conflict directly with scientific evidence. He describes faith as belief without evidence; a process of active non-thinking. He states that it is a practice that only degrades our understanding of the natural world by allowing anyone to make a claim about nature that is based solely on their personal thoughts, and possibly distorted perceptions, that does not require testing against nature, has no ability to make reliable and consistent predictions, and is not subject to peer review.