What are the efforts and difficulties of a theological reflection on mission? This volume is a manual of missiology, without the pretense of being conclusive. It sets out to answer the requirements of a systematic and unifying synthesis of missiology. It deals with the theology, spirituality, pastoral work, canon law, vocation, animation, cooperation, institutions and organizations for mission. This study intends to address the challenges of a new evangelization, in particular interreligious dialogue, inculturation and globalization. These pages are the fruit of years of research, teaching and missionary commitment.