In this paper, I will try to exploit the implication of Leibniz's statement in Monadology (1714) that "there is a kind of self-sufficiency which makes them [monads] sources of their own internal actions, or incorporeal automata, as it were" (Monadology, sect.18). Leibniz's monads are simple substances, with no shape, no magnitude; but they are supposed to produce the phenomena resulting from their activities, which for us humans look as the whole world, the nature. The activities of a monad are characterized by mental terms, perceptions (internal states) and appetites (which change the internal state). By means of perceptions, a monad becomes a "perpetual living mirror of the universe"; it can receive the information of other monads and it ...