"Ah, sinner that I am!" said Don Quixote, "how bad it looks in governors not to know how to read or write; for let me tell thee, Sancho, when a man knows not how to read, or is left-handed, it argues one of two things; either that he was the son of exceedingly mean and lowly parents, or that he himself was so incorrigible and ill-conditioned that neither good company nor good teaching could make any impression on him.
There are no more uses of "incorrigible" in the book.
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She was declared an incorrigible delinquent and sent to reform school.
Incorrigible drunk driver sentenced to life in prison