The absence of good (Latin: privatio boni), also known as the privation theory of evil, is a theological and philosophical doctrine that evil, unlike good, is insubstantial, so that thinking of it as an entity is misleading. Instead, evil is rather the absence, or lack ("privation"), of good. This also means that everything that exists is good, insofar as it exists; and is also sometimes stated as that evil ought to be regarded as nothing, or as something non-existent.

It is often associated with a version of the problem of evil: if some things in the world were to be admitted to be evil, this could be taken to reflect badly on the creator of the world, who would then be difficult to admit to be completely good. The merit of the doctrine in serving as a response to this version of the problem of evil is disputed.