By St. John Paul II, Evangelium Vitae (1995) - The Lord said to Cain: “What have you done? The voice of your brother’s blood is crying to me from the ground” (Gen 4:10).The voice of the blood shed by men continues to cry out, from generation to generation, in ever new and different ways... The Lord’s question: “What have you done?”, which Cain cannot escape, is addressed also to the people of today, to make them realize the extent and gravity of the attacks against life which continue to mark human history; to make them discover what causes these attacks and feeds them...