Since Vatican II the restored Permanent Diaconate in the Latin Church has played an increasingly important role in the life of the Catholic Church, particularly in Western Europe and North America. Is there a theology of the diaconate, and if so what are the contentious issues? How far is the diaconate really distinct from the priesthood and the ministry of laypeople? A way forward is to revive the subversive character of διακονία, both in practical pastoral ministry and in serious engagement with Catholic Social Teaching; this necessitates major changes to diaconate formation programmes. A clearly defined diaconate would be able to help the Church renew and reform its understanding of ministry.