This volume is probably not of interest to non Christians unless they happen also to be students of medieval western history or of the histories of religions. Eastern Christians may find the documents of interest as they illustrate the ancient customs of the west still current in their eastern communities.
This remarkable volume was first published in 1965 as #XLVII in the Alcuin Club Primarily an historical review of developments as observed in customs and documents, it reviews the changes from ancient practices to the thought and practice more commonly known to western Christians today. It does not directly argue pro or con but notes the changes and accompanying thought. Appended documents may be of interest for liturgical study.
Christian initiation (baptism) was anciently followed directly by chrismation/confirmation and communion. This continued in the East as the bishop provided blessed sacramental oil to the presbyters/priests allowing them to annoint and lay on hands in the bishop's absence. In the west the bishop reserved the anointing/laying on of hands for himself for whenever he had opportunity to visit the parishes. The rest of the story develops from this variance of practice.