Leibniz on Monads

Leibniz headHerrenhaussen garden

"Monads are entirely indivisible... However, solitary monads do not exist. They are monads, not monks." Letter to G. Wagner, 3 March 1698 (Grua 395)

"Monads should not be confused with atoms. Atoms (as they are imagined) have shape. Monads no more have shape than do souls; they are not parts of bodies but requisites." Letter to F. Bierling, 14 January 1712 (GP VII 503).

"The monad, of which we shall speak here is nothing but a simple substance that enters into composites; simple, that is, without parts." Monadology, sec. 1

"Monads have no windows, through which anything could enter or leave. Accidents cannot be separated from substances or go about outside of them, as the sensible species of the Scholastics used to do. Thus neither substance nor accident can enter a monad from without." Monadology, sec. 7

"Moreover, it must be confessed that perception and that which depends on it are inexplicable in mechanical terms, that is, in terms of figures and motions. And supposing there were a machine, so constructed as to think, feel, and have perception, one could imagine it increased in size, while keeping the same proportions, so that one could go into it as into a mill. In that case, we should, on examining its interior, find only parts that work upon one another, and never anything by which to explain a perception. Thus, perception must be sought in a simple substance, and not in a composite or machine. Further, nothing but this (namely, perceptions and their changes) can be found in a simple substance. It is in this alone also that all the internal actions of simple substances can consist." Monadology, sec. 17