Why Do We Believe?

It’s surprisingly difficult to find a consistent and coherent definition of “belief.” Merriam-Webster’s dictionary defines it as “something that is accepted, considered to be true, or held as an opinion” and a “conviction of the truth of some statement or the reality of some being or phenomenon especially when based on examination of evidence.” But is a belief really the same as an opinion? They certainly aren’t always expressed as mere opinions; all too often we hold them with certainty. And how often are beliefs really based on evidence? That depends on what we mean by “evidence.”