Inspiration for this project was provided by the many teachers who struggled to explain principles of versification to me that at least one of us, and usually both, neither understood nor with any real conviction believed. Had it not become so unfashionable after secondary school to admit such ignorance, I could have begun this book much earlier; perhaps there would have been no need of it. Among others, I thank Ron Bernard, Sidney Evans, Percival Everett, Penelope Geng, my father, various Greens, Catherine Kelley, Seth Lerer, Michaeline Mulvey, Michael Peterson, Sandra Prior, Ray Romero, Laura Scavuzzo-Wheeler and family, Margaret Russett, and the students who struggled through classes that amounted to first drafts of this book. I am also most grateful to Barbara Hanrahan and to the readers, editors, copyeditors, and designers of the University of Notre Dame Press, who have been consistently helpful, cheerful, and amusing throughout this project.