Pope Francis said Friday that Catholics should look to their own consciences more than Vatican rules to negotiate the complexities of sex, marriage and family life, demanding the church shift its emphasis from doctrine to mercy in confronting some of the thorniest issues facing the faithful. In a major church document entitled “The Joy of Love,” Francis made no explicit change in church doctrine and upheld church teaching on the lifelong bond of marriage between a man and a woman. But in selectively citing his predecessors and emphasizing his own teachings in strategically placed footnotes, Francis made innovative openings in...