True comprehensive understanding of the liturgy – and this also applies to reality in absolute terms – is not just an intellectual process. After all, the person is not made up of only reason and will, but also of body and senses. Therefore, if every single text of a liturgy celebrated in a sacred language is not understood – naturally excluding the biblical readings and the homily – in any case the whole event, the singing, the furnishings, the vestments, and the sacred place, whenever they give adequate expression to the celebration, touch the profound dimension of man in a much more direct way than comprehensible words can. Unlike in [past] time, today this is much simpler, since those who attend Mass already know the structure of the rite and the texts that recur in the liturgy, so when they participate in a Latin Mass they know enough about what is going on.
That Latin should be rejected as a liturgical language because it is not understood is therefore not a convincing argument, all the more so in that, despite all the difficulties relative to translation, the liturgy in the vernacular need not be abolished. Except that, as Vatican Council II says, Latin should not be abolished either.
On the other hand, what is the situation of “participatio actuosa,” meaning the active participation of the faithful in the liturgical celebration? The Council prescribes that the faithful must be able to sing or recite their parts in Latin as well. Is this an excessive request? If one thinks about how familiar the words of the texts of the ordinary of the Mass are, it should not be difficult to recognize them behind the Latin words.
At bottom, “participatio actuosa” means much more than merely talking and singing together: it is rather making one’s own, on the part of the Christian who participates in the function, the same intimate disposition of the sacrifice to the Father in which Christ accomplishes his giving of himself to the Father. And this is why the foremost need is for what Johann Michael Sailer has defined as the fundamental language of the Mass.
Under this aspect the Latin missal is also necessary from a practical point of view: the priest who goes to countries whose language he does not know should have the possibility of celebrating Holy Mass there too, without being forced to perform linguistic acrobatics unworthy of a liturgy.
In short: the Roman missal in Latin must be wished present in every church.
Translation taken from here.
Original German text here or here (pages 192-196)