|monad (ˈmɒnæd, ˈməʊ-)|
|—n , -ads, -ades|
|a. any fundamental singular metaphysical entity, esp if autonomous|
|b. (in the metaphysics of Leibnitz) a simple indestructible nonspatial element regarded as the unit of which reality consists|
|c. (in the pantheistic philosophy of Giordano Bruno) a fundamental metaphysical unit that is spatially extended and psychically aware|
|2.||a single-celled organism, esp a flagellate protozoan|
|3.||an atom, ion, or radical with a valency of one|
|[C17: from Late Latin monas, from Greek: unit, from monos alone]|
monad mo·nad (mō'nād')
An atom or a radical with a valence of 1.
A single-celled microorganism, especially a protozoan of the genus Monas.
Any of the four chromatids of a tetrad that, after the first and second meiotic divisions, separate to become the chromosomal material in each of the four daughter cells.
(from Greek monas "unit"), an elementary individual substance that reflects the order of the world and from which material properties are derived. The term was first used by the Pythagoreans as the name of the beginning number of a series, from which all following numbers derived. Giordano Bruno in De monade, numero et figura liber (1591; "On the Monad, Number, and Figure") described three fundamental types: God, souls, and atoms. The idea of monads was popularized by Gottfried Wilhelm Leibniz in Monadologia (1714). In Leibniz's system of metaphysics, monads are basic substances that make up the universe but lack spatial extension and hence are immaterial. Each monad is a unique, indestructible, dynamic, soullike entity whose properties are a function of its perceptions and appetites. Monads have no true causal relation with other monads, but all are perfectly synchronized with each other by God in a preestablished harmony. The objects of the material world are simply appearances of collections of monads.
Learn more about monad with a free trial on Britannica.com.