Full Idea
Active force should not be thought of as the simple and common potential [potentia] or receptivity to action of the schools. Rather, active force involves an effort [conatus] or striving [tendentia] toward action.
Clarification
The 'schools' means the traditional Aristotelian view
Gist of Idea
Active force is not just potential for action, since it involves a real effort or striving
Source
Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.252)
Book Reference
Leibniz,Gottfried: 'Philosophical Essays', ed/tr. Arlew,R /Garber,D [Hackett 1989], p.252
A Reaction
This is why Leibniz is lured into making his active forces more and more animistic, till they end up like proto-minds (though never, remember, conscious and willing minds).
Related Ideas
Idea 12714 The substantial form is the principle of action or the primitive force of acting [Leibniz]
Idea 12723 The most primitive thing in substances is force, which leads to their actions and dispositions [Leibniz]
Idea 13095 Essence is primitive force, or a law of change [Leibniz]