In the ancient world, 'The Pillars of Hercules' marked the edge of the then-known world and the limits of
human knowledge. A Renaissance legend says the pillars bore the warning Ne plus ultra ("nothing further beyond") as caution to sailors not to venture beyond them.

This bronze sculpture of Hercules representing The Pillars of Hercules was created by artist Ginés Serrán Pagán, sculpture is located at Muelle de la Puntilla, Ceuta, Spain.

Geographically, the European Pillar was the Rock of Gibraltar & the North African Pillar: Jebel Musa [1]

In the Inferno, Dante condemns that ancient Greek prideful intellect that illuminates but also consumes, which was embodied by Ulysses whose hubristic fire incited his boundless quest for experience & thirst for knowledge beyond the mythical Pillars of Hercules.

And yet Virgil stops Dante from speaking to that "fiamma antica" (ancient flame) emanating from Ulysses as Dante's intellectual pride is tempted by his mastery of speech & the Greek hero's "folle volo" (flight of folly) into untravelled worlds where forbidden knowledge awaits.

Detail of an actress holding a cauldron with the Olympic flame at the Temple of Hera on September 29, 2013 during the lighting ceremony of the Olympic flame in ancient Olympia, Greece [1]

In a strikingly evocative image in Paradiso XXVII, Dante the Christian pilgrim looks down at Earth from the heavenly stars where he sees the  "il varco folle d'Ulisse ("the trace of Ulysses' folly") on the ocean like a marking calling on the innate human desire for knowledge.

The Italian philosopher Benedetto Croce once declared that “no one of his age was more deeply moved than Dante by the passion to know all that is knowable, and nowhere else has he given expression to that noble passion as in the great figure of Ulysses"

The above photo shows my ca. 1920's antique pair bust of Dante bronze-clad bookends, made by Pompeian Bronze Co. [1]