Monad

Monads serve as the metaphysical foundations of Gottfried Wilhelm Leibniz’s mature metaphysics. In doing so they play a metaphysical role similar to the metaphysical role of atoms in traditional atomist theories. Like traditional atoms, monads are true unities, naturally indestructible, and persist through changes in ordinary bodies. Unlike traditional atoms, monads are unextended, metaphysically prior to space, and immaterial.

Monads have perceptions, appetites and points of view. Leibniz distinguishes three kinds of monads on the basis of their representational capacities. The lowest kind of monad – ‘bare’ monads or ‘vegetative’ souls – only have perceptions so faint and confused that they are unable to enjoy distinct, conscious representations. Leibniz likens them to our minds when we are in a deep sleep or in a daze. The intermediate level of monad – sensitive monads or animal souls – have perceptions that allow them to enjoy conscious representations of distinct entities. The highest level of monad – minds or human souls – enjoy higher-order thoughts. In virtue of such higher-order thoughts, minds are able to think about their perceptions, themselves and necessary truths.