The assertion or belief that physical and biological systems observed in the universe result from purposeful design by an Intelligent Being (God) rather than from chance or undirected natural processes.

Intelligent design (ID) is an anti-evolution belief that asserts that naturalistic explanations of some biological entities are not possible and such entities can only be explained by intelligent causes.

Advocates of intelligent design maintain that their belief is scientific and provides empirical proof for the existence of God. They claim that intelligent design should be taught in the science classroom as an alternative to the science of evolution.