he is correct to some extent. There were master craftsmen who could not read. I doubt the men who forged the finest katana in Japan were much good at reading. However, they were highly educated in making iron into folded steel, and and what temperature (done by color) steel needed to be brought to in order to create the best edge and the strongest sword.
In modern society, it is difficult to believe someone could be educated without being able to absorb written information. But many societies, in the course of history, had very wise individuals who could not read. If I recall correctly, until Seqoia developed it, most Native Americans had no writing. Were some of those people educated? of course. Many harvard PhDs would starve to death if you put them in a 40,000 acre forest alone and with no modern communication devices. IN that situation, those men would be UNEDUCATED. Now a Shawnee or Huron in the same situation would probably have been far more educated on how to feed himself, make a shelter, and find his way back to his people