Full Idea
The substantial form is the principle of action or the primitive force of acting.
Gist of Idea
The substantial form is the principle of action or the primitive force of acting
Source
Gottfried Leibniz (De Mundo Praesenti [1686], A6.4.1507-8), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 3
Book Reference
Garber,Daniel: 'Leibniz: Body, Substance, Monad' [OUP 2009], p.124
A Reaction
The clearest statement of the modification of Aristotle's hylomorphism which Leibniz preferred in his middle period, and which strikes me as an improvement, and about right. Shame that monads got too much of a grip on him, but he was trying to dig deeper.
Related Ideas
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]
Idea 13193 Active force is not just potential for action, since it involves a real effort or striving [Leibniz]