Monad may refer to: In philosophy: * Monad (Greek philosophy) a term meaning "unit" used variously by ancient philosophers from the Pythagoreans to Plato, Aristotle, and Plotinus to signify a variety of entities from a genus to God. * Monism, the concept of "one essence" in the metaphysical and theological theory * Monad (Gnosticism), the most primal aspect of God in Gnosticism * Monadology, a book of philosophy by Gottfried Leibniz in which monads are a basic unit of perceptual reality * Monadologia Physica by Immanuel Kant * The Cup or Monad, a text in the Corpus Hermetica