In Chapter 25, there is a contrast made between those who are educated in the person of Mr. Underwood and those who lack education in the person of Bob Ewell.
As an anecdote to illustrate what having an education means in the true sense of the word--the act of leading out (of ignorance) [e in Latin =out of/ -duct- = to lead/ -tion= the act of], there was in the late 1990's an inmate of a federal prison who was able to earn two college degrees through correspondence courses. After he procured these degrees, he told one of the employees,
I believe if I had gone on in school and earned a college degree before I turned twenty-one, I would not be imprisoned right now because I have come to understand that education takes you down different avenues of thinking.
Indeed, Mr. Underwood and Bob Ewell have traveled "different avenues of thinking" after the trial although they were both in accord beforehand in their hatred for African-Americans. But, after the trial, having heard the evidence and the testimony of the gentle and kind man, Tom Robinson, Mr. Underwood becomes aware of his generalized thinking as having some flaws. So, in his editorial in the Colored News of his newspaper, Mr. Underwood demonstrates that he has learned that
...it is a sin to kill cripples, be that standing, sitting, or escaping. He likened Tom's death to the senseless slaughter of songbirds by hunters or children....
On the other hand, Bob Ewell, who was belittled because of his own hypocrisy, has learned nothing from his lies and remains ignorant and uneducated. Furthermore, he is more set upon retaliation against Atticus for embarrassing him than upon justice. And, of course, he has no remorse over the outcomes of the trial.
...Mr. Ewell said it made one down and about two more to go as he vows to avenge himself upon Atticus.