The second aspect will be dealt with in the next and last post of this series. Now I want to dwell a bit on the ‘fundamental angelological problem’: How do we explain that supernatural beings can serve as the (efficient) cause of changes in the natural world.
Two approaches can be distinguished: Descartes proposes a partial ‘reenchantment’ of nature (if it is appropriate to borrow this term from John McDowell). Nature is thought as something that is to a certain extent susceptible to supernatural influence - matter has a (supernatural) receptivity for acts of the angelic will. Hobbes and Leibniz try to naturalise the supernatural by applying the ‘principle of locality’: Only those things are part of the world (Leibniz) or universe (Hobbes) that are (Hobbes) or stand in a relation to (Leibniz) a body. But for Hobbes, only the angels in the Old Testament can be explained away as supernaturally caused natural phenomena that are similar to spectres or delusions. Leibniz is closer to Hobbes than some may have suspected beforehand: Angels are natural phenomena (minds that can change their bodies more easily than humans).
Nevertheless, there are limits for such rationalisations: Hobbes must bow to the authority of Scripture. Spiritual embodied substances (angels in the New Testament) may exist. So we cannot be sure that all changes in the world can be explained by the movement of bodies. Leibniz has to take God’s omnipotency into account. He is forced to concede the possibility that angelic entelechies may exist even though they stand in no relation to a phenomenal body. Such angels may not be part of this world (depending on how we interpret the requirement that the activity of an entelechy must be limited by prime matter). Hence, we cannot deny that there may be ‘supernatural’ angels. Their status within the worldview of natural philosophy is as dubious as it is in Hobbes.
In sum, an integration of angels into a mechanistic philosophy of nature comes at a prize: Descartes’ approach seems to water down the explanatory force of mechanism, because matter is endowed with a receptivity for the supernatural. Hobbes must bow to the authority of Scripture and admit the possibility of embodied spiritual substances, even though his philosophy is built on the presupposition that the universe is but an aggregate of bodies.