Both image and quote are worth being dwelt upon.
O ye who have undistempered intellects,
Observe the doctrine that conceals itself
Beneath the veil of the mysterious verses!
Inferno: Canto IX
Note: The image appears on the Barnes & Noble Classics 2008 hardcover edition of Dante’s The Divine Comedy in the Henry Wadsworth Longfellow translation with reproductions of Gustave Dore’s engravings from the 1867 edition.