"Nullius addictus iurare in verba magistri, quo me cumque rapit tempestas, deferor hospes."
"As I am not obliged to swear allegiance to a master, wherever the storm drags me, I am turned in as a guest."
--Horace, Epistles, Book I, epistle I, lines 14 and 15
The much abbreviated version of this quote, Nullius in verba, was taken in 1663 as the motto of The Royal Society; in this usage, it is generally translated as 'on the word of no one' or, in the modern parlance, 'take nobody's word for it.' In other words, don't accept something just because it is said, whether by the masses, the political leaders, or the church. The truth should be discovered through exploration, logic, and experimentation. This charter was made much easier when the king joined the club.
Pronounced "nul-LIE-us en werba", although modern Western pronunciation prefers to produce it with a hard /v/.