re are beings which never rise above the condition of
deep sleep or stupor.

In conformity with this more inclusive meaning, perception is defined as
the representation of the external in the internal, of multiplicity in
unity _(representatio multitudinis in unitate_). The representing being,
without prejudice to its simplicity, bears in itself a multitude of
relations to external things. What now is the manifold, which is expressed,
perceived, or represented, in the unit, the monad? It is the whole world.
Every monad represents all others in itself, is a concentrated all, the
universe in miniature. Each individual contains an infinity in itself
_(substantia infinitas actiones simul exercet_) and a supreme intelligence,
for which every obscure idea would at once become distinct, would be able
to read in a single monad the whole universe and its history--all that is,
has been, or will be; for the past has left its traces behind it, and
the future will bring nothing not founded in the present: the monad is
freighted with the past and bears the future in its bosom. Every monad is
thus a mirror of the universe,[1] but a living mirror (_miror vivant de
l'univers_), which generates the images of things by its own activity
or develops them from inner germs, without experiencing influences from
without. The monad has no windows through which anything could pass in or
out, but in its action is dependent only on God and on itself.

[Footnote 1: The objection has been made against Leibnitz, and not without
reason, that strictly speaking there is no content for the representation
of the monads, although he appears to offer them the richest of all
contents, the whole world. The "All" which he makes them represent is
itself nothing but a sum of beings, also representative. The objects of
representation are merely representing subjects; the monad A represents the
monads from B to Z, while these in turn do nothing more than represent one
another. The monad mirrors mirrors--where is the thing that is mirrored?
The essence of substance consists in being related to others, which
themselves are only points of relation; amid mere relativities we never
reach a real. That which prevented Leibnitz himself from recognizing this
empty formalism was, no doubt, the fact that for him the mere form of
representation was at once filled with a manifold experiential content,
with the whole wealth of spiritual life, and that the quantitative
differences