The essay’s thesis: painters kept reaching for the same setting to do three different jobs across three centuries — holy retreat for hermit saints (Bosch, Velázquez), a stage for classical myth (Ingres’s Oedipus and the Sphinx, Eckersberg’s Ulysses fleeing Polyphemus), and, in Benjamin West’s 1772 “The Cave of Despair,” a symbol of ruin. The rock never changes; what painters ask it to mean keeps drifting toward plain observation as the Enlightenment wears on.