To defend the liturgical use of Latin is no easy task today. Traditionalists interpret so doing as an appeal to full-blown restorationism; those in the reform-of-the-reform camp see it as a means of cultivating a sacred aesthetic; self-described liberals see it either as crypto-restorationism (at worst) or a legitimate private intellectual exercise (at best).
Let me set out here part of my theory regarding liturgical language: a liturgical language is only proper to a given liturgy in so far as one has internalized the language. The language must elicit both an intellectual and emotional response. Added to this must be consideration of the local community, with due recognition that human beings posses the capability to learn.
The above having been stated, interest in liturgical Latin will prove a fruitless passing phase of religious culture desperate to find its next fix if the language is little more than an aesthetic device. To illustrate this point, there is a re-publication of a long out of print and highly sought after Latin-English "tridentine" breviary (Urban VIII's horrendous revision of the hymns included) which proves to be a cause for celebration among certain groups. I would contend, if this breviary will be used to follow along in English, then printing the Latin or celebrating the divine office in Latin is purely aesthetic - if the Latin has any true value, one ought to be able to pray it without referring to the English.
When Latin is internalized, when it readily elicits intellectual and emotional responses from its user, the power of the Latin language to communicate the numinous is palpable. In addition, it's quite liberating. No translation ever absolutely captures the dynamics of the original language - every language is a system to itself. When one has acquired a knowledge of the Latin language, one acquires a certain freedom away from the translation. If internalized, the Latin text becomes your language, subject to the dynamism of mind and heart and opens up a world of interpretive meaning closed through dependency of a translation.
One of the first hymns I worked on comes from the Liturgia Horarum. Week II, Saturday, Officium Lectionis, Lux aeterna lumen potens. When the first stanza hit me line by line I felt a sense of satisfaction one rarely receives:
Lux aeterna, lumen potens,
debellator atrae noctis,
By the time I had read this hymn, I no longer required a reference grammar nor dictionary. Yet, it wasn't that satisfaction alone. Liturgical Latin book ends to very distinct parts of my life, two ends to a long emotional journey. I read this hymn at a time when, in hindsight, a very dark chapter of life was closed and a new one had begun opening. At that moment, the hymn, this Latin text, bespoke of my own odyssey. Sitting in a coffee shop, the snow lightly falling in late March, as the words rolled through the mind, I stood at the threshold of unconquerable light, light from light.
The breviary, in its post-Vatican II form, was actually a frequent companion during this time. Consequently, no matter what language I work with, there is a quality to the psalter in the Latin breviary that cannot be reproduced. The psalms in Latin just make a certain sense, and some of them only "work" in Latin, psalms 24 and 66 in particular.
Every new language one acquires opens gates leading into a new world, a new perception of life and meaning. When one internalizes Latin, when the language elicits intellectual and emotional response, then Latin liturgy communicates the divine. Additionally, when one internalizes Latin, one is exposed to a wealth of spirituality that cannot be conveyed via translation. The reason to defend liturgical Latin, the reason to promote its acquisition, is the otherwise untranslatable spirituality. Every language creates a spirituality unique to itself. There is a good deal in Roman Catholicism that does not make much sense without going back to the Latin.
This having been said, liturgy, prayer, spirituality, these are not one way linguistic streets. No single language has a monopoly, Latin in the Church of Rome included. While Latin dominated the Roman liturgy for some 1600 years, since at least the medieval period a parallel spirituality grew up around the various vernacular languages each with a significant number of nuisances to lean away from the dominate liturgical-spiritual model. "Holy Cards" actually provide us with a good example of this. "Holy cards," afford us, at times, multiple views at how a given linguistic/cultural/ethnic block interpreted various elements of the dominate liturgical-spiritual model. The prayers found on the backs of holy cards oftentimes diverge from the "official" model as found in missal, breviary, or martyrology and, in face, differ among linguistic/cultural/ethnic blocks. The advent of the vernacular as the dominant praxis for liturgy and prayer in Roman rite suddenly situated "local Catholicism" into officialdom.
In any given region of the globe, the Roman rite now interacts with what was for generations a parallel liturgical or spiritual tradition inexorably connected to the local language. This has had consequence whose final results have still to be determined. While various texts just aren't the same as when they're in Latin, I must say that, in toto, the Roman Rite only seems to fit for me in its Italian variant. It only makes sense, it only sits well, it only communicates the divine in every aspect when in Italian...for me, that is. I cannot give you any well described account as to why this is so. Perhaps because despite the diaspora of Italians, I still feel more of a sense of identity with my ancestry than my host culture. I can't say much more than that. What I can state: for many people, vernacular Catholicism works and they have no interest in learning Latin or opening that vista of reality...they also have no interest in learning Italian, which for my life, I cannot comprehend!
The vernacular is still a recent thing for the Roman rite and since the Roman rite has no single ethnic/cultural/linguistic block, the effects will take a long time to fully appreciate. In large part, the Roman rite must reckon with various linguistic models of prayer, spirituality and indeed liturgy that it had long forced to the margins. In the mean time, for my liturgical observance, the Liturgia Delle Ore captures it best:
O re d'eterna gloria,
che irradi sulla Chiesa
i doni del tuo Spirito,
assisti i tuoi fedeli
Illumina le menti,
consola i nostri cuori
rafforza i nostrt passi
sulla via della pace.