34 NATURE AND LIFE. 
atoms of substance, that is, real unities, absolutely devoid 
of parts, which are the sources of action, the first principles 
in the composition of things, and the last elements, so to 
speak, in the analysis of substances. These might be 
called, as Leibnitz calls them, metaphysical points: they 
possess some vitality, and a kind of perception; and mathe- 
matical points are the mode employed in using them to 
express the universe; but, when corporeal substances are 
_ compressed, the aggregate of their organs makes but one 
physical point, as we regard it. Thus physical points only 
seem to be indivisible, but are not really so; mathematical 
points are exact, but they are only modes of thought. 
Nothing is complete and real except metaphysical points, 
or points of substance (the forms or souls of Leibnitz), and 
without them no reality would exist, since without true 
units there can be no multitude. 
Points of substance, or monads, without extension or 
form, are then truly the inner and specific forces of things. 
We can conceive them, but cannot shape their image. Just 
as we should be incapable of knowledge if we had not the 
signs of language, so, without the support of those repre- 
sentations to the senses furnished by body and motion, we 
must remain ignorant of force. They do not, however, 
help us to escape the inference that force is the reality of 
which body and motion are merely the concrete and sen- 
sible images, not intelligible ones. Briefly, there is some- 
thing more in the world than a display of phenomena, some- 
thing more than visible forms and express motion: there is 
energy, spring, concealed activity at rest, concentrated and 
- condensed inner potency, ever ready to be translated into 
numberless appearances. Beyond perception and without 
extension, these mother-forces, fertile sources of all action 
and all life, compose, as Leibnitz teaches, the very essence 
of things. 
How do these forces engender bodies and souls, and 
