The primordial darkness of the universe at the moment before creation, as represented in a plate in Robert Fludd’s 1617 Utriusque Cosmi Maioris scilicet et Minoris Metaphysica, Physica, atque Technica Historia (The Metaphysical, Physical, and Technical History of the Two Worlds, Namely the Greater and the Lesser). The words Et sic in infinitum (“and like this to infinity”) are written on all four sides of the square.