This revised and updated work on the Eucharistic celebration incorporates insights of recent research, and has reformulated many passages in light of some important changes in thought and language since the first edition. The book helps readers gain an understanding of correct form for celebration of the Eucharistic liturgy in light of the renewals of Vatican Council II. It is, therefore, an "explanation of the Mass, " as Pius Parsch, to whom the first edition was dedicated, understood it. It is an explanation both of the biblical foundations and the historical development of the liturgy within its 2000-year tradition. The intent of the book is practical: it is meant as an aid to an appropriate and responsible celebration of the congregational Eurcharist. It includes a reminiscence of Professor Johannes H. Emminghaus (1919-1989).