Clifford Longley (8 March) queried whether the Theology of the Body developed by Pope John Paul II could do anything towards renewing marriage and family life. He found that theology to be “defiantly unempirical”, and came from someone who knew “nothing about sex from personal experience”. But the late Pope could also prove himself defiantly empirical in matters of sex.My brother James O’Collins was one of the busiest urologists of his generation. He contributed to the remarkable progress in treating the urinary system made during his four decades in that field of surgery. Back in 1989, when I was well into years of teaching at the Gregorian University, Jim turned up in Rome to attend a medical conference sponsored by the Pontifical Council for Health Care. I