Our learning has come from those without learning - nor judgment, sense or comprehension. Devoid of understanding, they give explanations, and without learning of their own they give instructions. All their learning is forged and feigned, and there is no slander they won't drum up and pass on. Being ignorant, they think themselves learned, and find fault with those whose learning is sound:
"Busy in all things, he masters none of them.
His guidance increases in nothing but error."
What is more, without his pretensions to being the wisest of men, his drivel brings him no pleasure. In reality he is a blight on his students, and to those seeking an education he is poison. In his mind, however, even an assembly of his own preceptors would be in need of his instruction. When he narrates, he prevaricates, and when questioned he vacillates. When disputed he yells, when contradicted he brawls, and when the proof against him is decisive he answers with foul language.
"He attacks and advances without awareness or knowledge.
What else is stupidity, if not that?"
The ignorance of such preceptors is off the scale established by al-Khalil when he declared the rankings of men, as related by Muhammad ibn Yahya ibn al-'Abbas [al-Suli] on the authority of Abu Ahmad Muhammad ibn Musa al-Barbari, on the authority of al-Zubayr ibn Bakkar [ibn al-'Awwam] who was told by al-Nadr ibn Shumayl:
"I heard al-Khalil say: 'Some people have knowledge, and know that they have knowledge. These are the learned, who should be followed. Some have knowledge without knowing that they have it; such people go astray, and should be led aright. Some do not have knowledge, and know that they lack it. These are the students, who should be taught. And some have no knowledge, and do not know that they lack it. These are the ignorant, and they should be avoided.' "
From The Classes of Grammarians by Abu 'l-Tayyib al-Lughawi