Darkness
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.
The black page from Robert Fludd’s Utriusque cosmi maioris scilicet et minoris metaphysica, physica atque technica historia, published in Oppenheim 1617