A master of wit and wry humor on the page, Mark Twain also gained acclaim as a speaker throughout his literary career. Twain delivered this address on theoretical morality vs. practical morality to the New Vagabonds Club of London. With his signature tongue-in-cheek humor, he tells the audience that the only way to learn practical morality is by committing immoral acts in order to "vaccinate" oneself against committing them in the future. Presented with anecdotes from his childhood, this Twain speech masterfully walks the line between light-hearted humor and biting truth.