Book excerpt: The author of this book, Gerard Lukken, has always believed that liturgy is not something which is unchangeable or sacrosanct, something to be imposed 'from above'; rather he believes that it must gain shape and content from the situation in which believers find themselves. This involvement is reflected in the hundreds of publications which have flowed from his pen. Lukken's extensive writings offer not only an exciting reflection on the challenges (such as secularization and the decrease in church-going) confronting church and believers, but also on the problems they have faced in celebrating their faith in recent decades. Moreover, his work represents a model for methodological renewal. The key concepts in his theological approach and his evaluation are 'anthropology' and 'semiotics'. These two aspects have left their marks on the organisation of this book which is a selective compilation drawn from his earlier publications. This collection consists of nineteen studies which have lost nothing of their topicality and most of which are now being translated into English, French or German for the first time. By crossing the frontier of language in such a way the editors wish not only to honour a leading specialist in liturgy but also to contribute to academic research into liturgy throughout the world. Gerard Lukken (1933) studied at the Diocesan Seminary in Haaren (Noord-Brabant), the Pontificia Universita in Rome, and the Institut Superieur de Liturgie in Paris. He was professor of liturgy and sacramental theology (from 1967) and director of the Liturgical Institute (from 1992) at the Theological Faculty of Tilburg until his retirement in 1994.