Rev. Louis Bouyer (1913-2004) was a member of the French Oratory and one of the most respected and versatile Catholic scholars and theologians of the twentieth century.
He became a leading figure in the Catholic biblical and liturgical movements of the twentieth century, was an influence on the Second Vatican Council, and became well known for his excellent books on history of Christian spirituality. In addition to his many writings, Bouyer lectured widely across Europe and America.
An excellent exposition of Christian ritual, and why liturgy is inherently a natural, anthropological expression of God rather than limited to particular instances of divine revelation.
Though it's not so long it took me a lot of time to read this based on its density. Yet it's a good introduction to the fundamental anthropological, symbolic and religious aspects of liturgy drawing from Scripture, Jewish roots and psychology, philosophy and history.