Full Idea
The nature of substance necessarily requires and essentially involves progress or change, without which it would not have the force to act.
Gist of Idea
Substance must necessarily involve progress and change
Source
Gottfried Leibniz (New system of communication of substances [1695], p.144)
Book Reference
Leibniz,Gottfried: 'Philosophical Essays', ed/tr. Arlew,R /Garber,D [Hackett 1989], p.144
A Reaction
Bravo. Most metaphysical musings regarding 'substance' seem entirely wrapped up in the problem of pure identity, and forget about the role of objects in activity and change.