Overbelief is philosophical term for a belief adopted that requires more evidence than one presently has. Generally, acts of overbelief are justified on emotional need or faith, rather than evidence. It contrasts with the less-often debated concept, underbelief. Someone who fails to adopt a belief that they clearly have evidence for is committing underbelief. This idea originates from the works of William James in The Varieties of Religious Belief and refers to the conceptual framework that individuals have.