To understand what devotion is and what devotions are in the Modern Age, it is useful to go back to the Latin origin of the notion of «devotion», to what «devotio» was in Rome. Émile Benveniste devoted an entire chapter of his book on European institutions to «voto», «votum», «voveo». Going back to the Indo-European root «weghw» it is possible to find a double meaning relative to the thing that is the object of the solemn vow and to the guarantee requested in exchange for the «devotion»; and «devoveo», «devotio», designate the act of formulating a vow, of consecrating something to a god, and therefore at the same time something that one commits oneself to fulfill and that which one wishes to obtain in exchange from the deity. While we should not have a fetishistic conception of etymology, as if the materiality of a root contained a meaning capable of circulating through the centuries and transformations, we must not forget this double meaning of «devotion».
St. Thomas’ definition puts us on the track of the devotions that developed in the seventeenth century. The Summa, in fact, makes devotion an act of the virtue of religion; through devotion, man offers his will to God because, according to St. Thomas, the intelligence is consecrated to the service of God through prayer, the will through devotion and the body through adoration.
The writers of Saint-Nicolas du Chardonnet make denouncing false devotion one of the commonplaces of their spirituality; thus, Bourdoise writes: «Never had one seen so much devotion and so little Christianity. […] I have not yet seen any devotion that does not combat any obligation». Bourdoise criticizes not only «worldly» devotions, but all devotion, insofar as it is chosen, insofar as it is private and insofar as it competes with the liturgy, the office of the Church. Claude Fleury says essentially the same thing: «Devotion can only be superficial when it is not based on solid principles. […] It can never be too much to strive to preserve uniformity and to prevent the itch for new and singular devotions. This is what Claude Joly also wrote years before to Cardinal Bona: «The Church is governed by tradition, not by devotion; devotion can err, tradition never».
I invite everyone to read Matthias’ post on the topic of the day.