“The Sleep of Reason Produces Monsters (Spanish: El sueño de la razón produce monstruos) is an etching by the Spanish painter and printmaker Francisco Goya. Created between 1797 and 1799, it is the 43rd of 80 etchings making up the suite of satires Los Caprichos. Goya imagines himself asleep amidst his drawing tools, his reason dulled by slumber and bedeviled by creatures that prowl in the dark. The work includes owls that may be symbols of folly and bats symbolizing ignorance. The artist’s nightmare reflected his view of Spanish society, which he portrayed in the Los Caprichos as demented, corrupt, and ripe for ridicule.“
The full epigraph for capricho No. 43 reads; “Fantasy abandoned by reason produces impossible monsters: united with her, she is the mother of the arts and the origin of their marvels.”
From the Wikipedia article on Goya’s Los Caprichos, which we link here.