Absence of good

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. Evil, on this view, is parasitic upon the good whose absence or corruption it presupposes.

The theory is most closely associated with late antique and medieval Christian thought, especially Augustine of Hippo, who adapted Neoplatonic ideas (notably from Plotinus) and argued that evil is a privation of the goodness that God has created in all things. It was further developed by figures such as Boethius, Pseudo-Dionysius, John of Damascus, and Thomas Aquinas, and later taken up—often in modified forms—by early modern philosophers like Spinoza and Leibniz.

Versions of the privation theory are also found outside historic Christian thought, for example in the Baháʼí Faith, whose authoritative texts describe evil as "nonexistence" or "nothingness". In contemporary philosophy of religion, the privation theory has been re-developed and defended in detail, particularly within neo-Thomist metaphysics.

Because the theory denies that evil is a positive reality created by God, it is often discussed as a response to the problem of evil. If evil is a privation of good rather than a thing made by God, then God is said to create only good, and to permit the privations that constitute evil. Critics argue, however, that the theory struggles to account for the apparently "positive" character of many evils, such as intense pain or sadistic cruelty, and that it provides at best a partial theodicy.