Continuity or Discontinuity? Some Remarks on Leibniz's Concepts of Substantia Vivens and Organism

The doctrine of natural machines, of organisms, of composite substances, assumes a marked consistency in Leibniz starting from his mature years (let us say, from the publishing of New System in 1965 onwards). There is no doubt, therefore, that for a full explanation of the conceptual content of the reflection of Leibniz on the nature of living substances we must turn to the “classic” places in which it took form: from the letters to De Volder and Lady Masham of the early 1700s, to the Nouveaux Essais, to Animadversiones contra Stahl and, naturally to Princìpes de la Nature et de la Grace and to the Monadologie. We can in any case ask what are the elements of specific difference are that emerge in this vast doctrinal corpus regarding those elements of the theory of the living being that had already appeared with a certain frequency in the texts of the early 1780s. Put in other words: what link of continuity subsists between the proto-theory of the living being of the ‘80s and that of the mature years (let us say from New System on)? Or, overturning the formulation of the problem: what elements of discontinuity suddenly break into Leibniz’s reflections from the second half of the ‘90s compared to the immediately preceding phases of his thought? Certainly, the monads, the machines of nature. But is it possibile to focus even more clearly the lens of our observations? I mean: after a decade of intense theoretical debate on the nature of corporeal substances, on organisms, on machines of nature, is it possibile to sketch a historical picture that accounts in a coherent manner for the development of Leibniz's thought in relation to the questions raised here?