Virgil - Felix Qui Potuit Rerum Cognoscere Causas
“Felix, qui potuit rerum cognoscere causas” is verse 490 of Book 2 of the "Georgics" (29 BC), by the Latin poet Virgil (70 - 19 BC). It is literally translated as: “Fortunate, who was able to know the causes of things”. ] Virgil may have had in mind the Roman philosopher Lucretius, of the Epicurean school.
The verse on display in the Catacombs of Paris
This sentence is often written with a present tense instead of the past tense: “Felix, qui potest rerum cognoscere causas” (“Fortunate is he, who is able to know the causes of things”). Translators have also often added the adjective "hid" or "hidden" to qualify the causes.
The latter half of the phrase, "rerum cognoscere causas", is the motto of the London School of Economics, the University of Sheffield, Bruce Hall (residential college of the Australian National University), Humberside Collegiate, the University of Guelph, Hill Park Secondary School in Hamilton, Ontario, the IVDI lecture hall of the University of Debrecen, the Science National Honor Society, the Royal Military College of Science, the German newspaper Der Tagesspiegel and the Romanian National Defense College [ro].