Full Idea
There are only atoms of substance, that is, real unities absolutely destitute of parts, which are the source of actions, the first absolute principles of the composition of things, and, as it were, the final elements in the analysis of substantial things.
Gist of Idea
The analysis of things leads to atoms of substance, which found both composition and action
Source
Gottfried Leibniz (New system of communication of substances [1695], p.142)
Book Reference
Leibniz,Gottfried: 'Philosophical Essays', ed/tr. Arlew,R /Garber,D [Hackett 1989], p.142
A Reaction
I like this because it addresses the pure issue of the identity of an individuated object, but also links it with an active view of nature, and not some mere inventory of objects.