Three Knowledges

"I wondered, however, if the Second Knowledge, that of the intellectuals, might not be as carefully tailored to preclude inquiry on their level as the First Knowledge apparently was to preclude inquiry on the level of the Lower Castes. I would guess that there is a Third Knowledge, that reserved to the Priest Kings."

First Knowledge - This is the education available to the lower castes such as the Peasants; it is practical if occasionally deliberately erroneous such as the idea that Gor is a flat disk. Also they are much more superstitious, embracing the idea that knowing man's real name gives one power over them, a capacity to use the name in spells or insidious magic practices. This being the case they have two names, their real name and their "use name".

She now began to be instructed in what is known as the First Knowledge, which is that level of understanding common to most individuals on this world, a knowledge of myths, stories, and popular lore. Prize of Gor

I nodded. Many Goreans, particularly those limited to the First Knowledge, have “use names” to conceal their real names, for fear the real names might somehow be used against them, perhaps in spells. Too, it should be noted that the names given were not unusual on Gor. I had known others who bore those names, particularly Quintus and Fabius. Those names are common in Ar. The names might have been altered, too, of course, simply to obtain the convenience of an alias. Swordsmen of Gor

Second Knowledge - This is the education available to the higher castes; it is more esoteric and includes knowledge of Earth. Most High Castes posses 'Double Knowledge', both First and Second Knowledge

The sun was now dipping into the grasslands in the west, as the sun, Tor-tu-Gor, Light-Upon-the-Home-Stone, the common star of Gor and Earth, now took its rest after its diurnal labors, as the first knowledge would have it, or, as the second knowledge would have it, as the planet rotated eastward. There is rumored to be a third knowledge, as well, but it seems that this is reserved to those whom the men of this world commonly speak of in hushed tones, the Priest-Kings of Gor. Prize of Gor

Third Knowledge - This education is reserved for the Priest Kings. A comprehensive knowledge of the existence and practices of the planets Earth and Gor, the nature and methods of the races of Priest Kings and Kurii, and the distinct relationship which exists between the occupants of Earth and those of her sister planet, the Counter-Earth Gor. Available only to those few who work in the service of the Sardar, or who have, through extraordinary circumstances, been able to exist and pursue practical and philosophical knowledge upon both worlds.