To what extent was Twain justified in striking Brown, even though that was breaking the law?
After he has had the experience of meeting many a captain and other interesting individuals, Twain considers himself fortunate for having done so because whenever he reads about a certain character, he thinks to himself, "I know him." So, in his continuing education on humanity, he becomes a cub pilot for a man named Brown.
He was a middle-aged, long, slim, bony, smooth-shaven, horse-faced, ignorant, stingy, malicious, snarling, fault hunting, mote-magnifying tyrant. (19)
One day when Twain's brother Henry, who is a clerk, comes to the pilot house in order to give Brown the message that the captain wants him to stop at a landing about a mile up the river. But, Brown ignores the boy; also, he probably does not hear him because he is partially deaf. Shortly after Brown passes the landing, the captain appears, asking why the boat has not stopped as instructed. The pilot claims no one has told him; the captain then asks, "Didn't you hear him?"
An hour later, Henry returns and Brown confronts him, but Henry declares that he did, indeed, pass on the message of the captain. This retort angers the malicious Brown and he throws a heavy chunk of coal at the boy. Twain then strikes Brown and hits him with a stool. Even when the pilot springs up and grabs the wheel of the boat, Twain is undaunted, instead lighting into his poor speech patterns.
Later, the captain asks the cub pilot Twain about his behavior; Twain admits to his deeds, but the captain replies,
I'm deuced glad of it! Hark ye, never mention that I said that. You have been guilty of a great crime; and don't you ever be guilty of it again, on this boat. But—lay for him ashore! Give him a good sound thrashing, do you hear? I'll pay the expenses. Now go—and mind you, not a word of this to anybody. Clear out with you!—you've been guilty of a great crime, you whelp!'
Apparently, the captain also feels that Twain is justified in his attack against Brown, who is abrasive and cruel and, therefore, deserving of punishment. Sadly, after Twain goes ashore, he later learns of the fire on board and the death of his brother.