The central act of the liturgy is the mass. It is an act in two senses, that of something done, and that of drama in the highest order. But despite the amount written round it in recent years, the idea of being a spectator only still infects many, perhaps the majority, of lay men and women. The mass remains a service which we attend, not a sacrifice which we offer. Some of this vagueness is due to the care necessary in separating the priest from the people, in that we say the priest alone has a priestly function, by ordination, while the people are in no way priests, even though they too share in the offering. This is inclined to cloud the part of the people, to obscure the public nature of the mass. For the mass is by nature public and social, whether it is said in the solitude of the Sahara by Charles de Foucauld or in the Piccadilly-Circus crowd of a London Midnight Mass. The priest offers sacrifice for the whole Church, for the living, for the dead.