Best, most up to date book on the subject. 2 nihil obstats, 1 imprimatur, 2 Bishop recommendation forewards. Each of the three authors are current professors of Philosophy or Theology. Fr Ronald Lawler is adjunct Professor of Theology at Franciscan University at Stuebenville. William E May is Professor of Moral Theology at the Pope John Paul II Institute for Studies on Marriage and Family in Washington DC. Another author Joseph Boyle, the third author, is the principal(dean) of St. Michaels College in Toronto where he is also Professor of Philosophy. A good book on Catholic Sexual Ethics from a respected Catholic Publisher: Our Sunday Visitor.