Leibniz, "Monadology (primary matter)"
Leibniz characterizes monads as metaphysical points, animate points or metaphysical atoms. In contrast to those physical atoms postulated by classic atomism they are not extended and thus are no bodies. But, as Leibniz explains in his letters to Burchard de Volder and Bartholomew des Bosses, this does not imply, that monads are immaterial.
Monads rather consist of 2 principles:
- inseparable from each other and
- constituting together a complete substance or monad.
1. the innermost center of a monad, i.e. the mathematical point, where the entelechy, soul or spirit is located, is the inner form of a monad.
This form has no existence in itself, and
2. incarnatation in a physical point or an infinitesimally small sphere, which is the "vehicle of the soul". This hull consists of a special matter, called primary matter (materia prima, matière primitive).
The problem that monads are supposed:
- to have some kind of matter on the one hand, but
- to have any parts and no extension on the other hand,
is to be explained by the dynamic nature of primary matter.
Leibniz conceives primary matter in contrast to the second matter (materia secunda), i.e. extended and purely phenomenal bodies.
Primary matter is a very fine, fluid and elastic matter, which he identifies in his early "Hypothesis physica nova" (1671) with the aether, spiritus or matter of light, flowing anywhere through every body.
Strictly taken, this primary matter or matter of light does not consist in "extension, but in the desire to extension".
Thus, "the nature of light strives to extend itself".
_____________________________
http://www.philosophy.leeds.ac.uk/GMR/hmp/texts/modern/leibniz/monadology/monadology.html
http://en.wikisource.org/wiki/Catholic_Encyclopedia_(1913)/Monad