4 You are of course familiar with the fact, Venerable Brethren, that a remarkably widespread revival of scholarly interest in the sacred liturgy took place towards the end of the last century and has continued through the early years of this one. The movement owed its rise to commendable private initiative and more particularly to the zealous and persistent labor of several monasteries within the distinguished Order of Saint Benedict. Thus there developed in this field among many European nations, and in lands beyond the seas as well, a rivalry as welcome as it was productive of results. Indeed, the salutary fruits of this rivalry among the scholars were plain for all to see, both in the sphere of the sacred sciences, where the liturgical rites of the Western and Eastern Church were made the object of extensive research and profound study, and in the spiritual life of considerable numbers of individual Christians.
Source: Mediator Dei (Vatican.va)