The Summary of Physics Restored

112Those who, following the received opinion, maintain that the four elements of things oppose one another must admit a fifth as a knot and bond of concord, a herald and maker of peace. Otherwise, the elements could admit neither perfect mixture nor any tempering in the work of generation. Instead, they would wander aimlessly, without rudder or pilot, across Nature’s vast sea, finding neither harbour nor birth, and would thus deprive Nature’s procreative genius of its end.