PLENUM

, in Physics, signifies that state of things, in which every part of space, or extension, is supposed to be full of matter: in opposition to a Vacuum, which is a space devoid of all matter.

The Cartesians held the doctrine of an absolute Plenum; namely on this principle, that the essence of matter consists in extension; and consequently, there being every where extension or space, there is every where matter: which is little better than begging the question.