It is an essential multiplicity of entities.
There seems to be no stopping this dissociation of matter into multiplicities short of finding each ultimate entity occupying one individual point.

This essential multiplicity of material entities is certainly not what is meant by science, nor does it correspond to anything disclosed in sense-awareness.

It is absolutely necessary that at a certain stage in this dissociation of matter a halt should be called, and that the material entities thus obtained should be treated as units.

The stage of arrest may be arbitrary or may be set by the characteristics of nature; but all reasoning in science ultimately drops its space-analysis and poses to itself the problem, 'Here is one material entity, what is happening to it as a unit entity ?' Yet this material entity is still retaining its extension, and as thus extended is a mere multiplicity.

Thus there is an essential atomic property in nature which is independent of the dissociation of extension.