How does Douglass learn to use the white mans opposition as a benefit?

One instance in which Douglass uses the white man's opposition is in his desire to read. When Mr. Auld found out that his wife was teaching him his letters, he forbid her to continue with their lessons.

"Now," said he, "if you teach that nigger (speaking of myself) how to read, there would be no keeping him. It would forever unfit him to be a slave. He would at once become unmanageable, and of no value to his master. As to himself, it could do him no good, but a great deal of harm. It would make him discontented and unhappy."

Through these words, Douglass came to understand that withholding certain things, like an education, allowed the white man to hold power over the black man..... that in learning to read, he would be able to take back some of that power. Thus, Douglass responds;

"In learning to read, I owe almost as much to the bitter opposition of my master, as to the kindly aid of my mistress. I acknowledge the benefit of both."