What do the punk singer Henry Rollins, the Guatemalan writer Rodrigo Rey Rosa, the American authors Tobias Wolff, Tayari Jones, and George Saunders, the Canadian writer Sheila Heti, and the Russian poet Polina Barskova have in common? At some point they all studied the art of writing deeply with someone. The nearly seventy short essays in A Manner of Being, by some of the best contemporary writers from around the world, pay homage to mentors -- the...