Divine conservation
In Christian theology, divine conservation is the principle that God is responsible for maintaining the continued existence of the universe. In (modern) theological terms, it is the underpinning of the conservation of mass-energy, theologians holding that this principle of physics by definition does not deal in why a closed system continues to exist, only what happens within it as it does. God has a conserving power that is ever-present and exercised over the whole of creation.
One example modern formalism of divine conservation is given by Leibniz scholar Robert C. Sleigh Jr as two theses:
- For any finite individual substance x and time t, if x exists at t then God brings it about in toto that x exists at t.
- For any state of affairs α and time t, if α obtains in the created world at t and α's obtaining at t requires a cause, then God brings it about in toto that α obtains at t.
Sleigh Jr labelled the first thesis weak conservation and the second thesis strong conservation. Todd Ryan later adopted largely the same labelling, from Sleigh Jr.
Scholars such as Descartes, Leibniz, and Malebranche can be said to agree with this modern formalism to different extents. A reduced form of the principle that was earlier espoused by Durandus of Saint-Pourçain is labelled by Alfred J. Freddoso and others mere conservation. In the other direction, some followers of Descartes such as Louis de La Forge and Antoine Le Grand expanded the principle, as did Malebranche, into occasionalism. An outright oppositional thesis is that of existential inertia.
The history of the concept goes back to Aquinas, and it influenced early scientific ideas about conserved quantities. In the 20th century, it resurged in popularity in theological circles as a way for scientific theists to harmonize modern scientific principles with Christian doctrines. Not only as a way to support theistic evolution in the later 20th century, in the 1950s it provided centuries old theological support for the steady-state universe model via Aquinas' arguments about continuous creation as an aspect of God's creation of the universe from nothing.