King's Main Idea in this letter is to get an immediate change in the laws against black people and to end segregation once and for all.
Example of Logos
"Never again can we afford to live with the narrow, provincial 'outside agitator' idea."
Example of Ethos
"It was practiced superbly by the early Christians, who were willing to face hungry lions and the excruciating chopping blocks before submitting to certain unjust laws of the Roman Empire."
Most Effective Appeal
"When you suddenly find your tongue twisted and your speech stammering as you seek to explain to your six-year-old daughter why she can't go to the public amusment park that had just been advertised on the television.
Example of Pathos
All of the words are very strong in a negative way. The black people are being treated poorly which is why MLK is using some of these words in his letter.