The front of Salman Rushdie's Two Years Eight Months And Twenty Eight Nights has this image from Goya with the quote in the original Spanish that's in the picture - El sueño de la razón produce monstruos.
It seems an appropriate thought for our times.
The Kahn Academy has a description of the etching and how it was made. It is one of 80 prints called Los Caprichos (caprices) produced in 1799.
The Rushdie book adds that it is the 43rd Capricho and the full caption at Prado [the major art museum in Madrid] 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 New York School of Medicine:
"The meaning of the title, El sueño de la razon produce monstruos, has been debated, mainly because sueño can mean both sleep and dream. Known as a pintor filósofo, Goya may have intended to affirm the Enlightenment by saying that when reason sleeps, the imagination produces monsters resulting in madness. Or, he may have implied that reason alone without imagination leads to madness, even horror. Goya's favorite literary character Don Quixote is a good illustration of imagination without reason.
The symbolism of the animals in the picture supports the ambiguity of Goya's vision. The lynx is a symbol of secrets, known for its strong vision and hearing. The lynx and the bat carry supernatural, even satanic significance, but can represent good. The owl may indicate wisdom. But the owl, cat, and bat also stand for depression or melancholy. The large bat with the goat face in the upper right denotes a satanic element, as the goat is identified with the devil, see, for example, Goya's painting, The Witches' Sabbath (1797-98). Baudelaire said of Los Caprichos: "All those distortions, those bestial faces, those diabolic grimaces of his are impregnated with humanity" (Ciofalo, pp. 64-65).
Goya produced two other, similar drawings, part of a series called sueños (dreams) which became Los Caprichos (The Whims). He juxtaposes the real and the demonic in several other works, such as De Que Mal Morira? (Of What Illness Will He Die?) and Las Viejas (see annotations). For comparison with other classic works that comment on the link between depression, sleep, and devilish temptation, see Dürer, Melencholia I and The Temptation of the Idler (The Dream of the Doctor). For Goya's interest in mental illness, see Courtyard with Lunatics."