“A man of knowledge is one who has followed truthfully the hardships of learning,” [don Juan] said. “A man who has, without rushing or without faltering, gone as far as he can in unraveling the secrets of power and knowledge.”

“Can anyone be a man of knowledge?”

“No, not anyone.”

“Then what must a man do to become a man of knowledge?

“He must challenge and defeat his four natural enemies.”

“Will he be a man of knowledge after defeating these four enemies?”

“Yes. A man can call himself a man of knowledge only if he is capable of defeating all four of them.”

“Then, can anybody who defeats these enemies be a man of knowledge?”

“Anybody who defeats them becomes a man of knowledge.”

“But are there any special requirements a man must fulfill before fighting with these enemies?”

“No. Anyone can try to become a man of knowledge; very few men actually succeed, but that is only natural. The enemies a man encounters on the path of learning to become a man of knowledge are truly formidable; most men succumb to them.”

A conversation between don Juan Matus and Carlos Castaneda, from The Teachings of Don Juan: A Yaqui Way of Knowledge