Which version of the Little Office or Divine Office should I pray?
That’s up to what you feel called to pray, and what is approved by your spiritual director for you to pray. As for me, a spiritual director once told me that since I was not obligated to pray an Office as a religious or professed secular Third Order, I can feel free to pray whichever version I feel called to pray of the Office, whether it be one of the versions of the Little Office, or part or all of the Divine Office. The important part was that I was consistent with my prayer life. After praying many versions of the 1962 Divine Office, the Liturgy of the Hours, and different versions of the Little Office, I found that praying the Carmelite Rite Little Office as presented by Fr. Vincent McDonald was the office that felt the most “right” for me. I think it has to do with the fact that I feel called to the life of a Carmelite third order as their Rule was laid out in 1962, and these are the prayers that were required of the Third Order tertiaries at that time.
Is praying the Little Office liturgical for the laity?
According to the Vatican II document, Sacrosanctum Concilium, “…When this wonderful song of praise is rightly performed by priests and others who are deputed for this purpose by the Church’s ordinance, or by the faithful praying together with the priest in the approved form, then it is truly the voice of the bride addressed to her bridegroom; It is the very prayer which Christ Himself, together with His body, addresses to the Father. Hence all who render this service are not only fulfilling a duty of the Church, but also are sharing in the greatest honor of Christ’s spouse, for by offering these praises to God they are standing before God’s throne in the name of the Church their Mother.”
In addition, Sacrosanctum Concilium states that “They too perform the public prayer of the Church who, in virtue of their constitutions, recite any short office, provided this is drawn up after the pattern of the divine office and is duly approved.” The Catechism of the Catholic Church references this passage when stating, “In this ‘public prayer of the Church,’ the faithful (clergy, religious, and lay people) exercise the royal priesthood of the baptized. Celebrated in “the form approved” by the Church, the Liturgy of the Hours “is truly the voice of the Bride herself addressed to her Bridegroom. It is the very prayer which Christ himself together with his Body addresses to the Father.”
In the Apostolic Letter Summorum Pontificum, Pope Benedict XVI states that “Ordained clerics may also use the Roman Breviary promulgated in 1962 by Blessed John XXIII.” In Universae Ecclesiae, there is further clarification from the Ecclesia Dei offices that “the use of the liturgical books proper to the Religious Orders which were in effect in 1962 is permitted”.
No formal consensus has been officially released from the Vatican or any other ecclesiastical authority stating that when laity prays the Little Office of the Blessed Virgin Mary that it is being prayed liturgically, although arguments have been made for the designation of the prayer being liturgical due to Articles 84 and 98 of Sacrosanctum Concilium. Technically there have been “new” editions of the Little Office published since Sacrosanctum Concilium, including three editions prepared by English Province of the Carmelites (O.Carm). However, religious orders are now encouraged to adapt the Liturgy of the Hours instead of allowing the prayer of the Little Office as fulfilling the religious obligation for the prayer of the Divine Office. Of the major Third Orders and Tertiary groups associated with religious orders, it appears that only some of the chapters of the Secular Order of Franciscans allow the prayer of the Little Office to fulfill their prayer obligations in their current rule.
Whether it is liturgical prayer or not, however, does not negate the fact that any prayer tied to the liturgy of the church, even if prayed purely as a devotion by the laity, will mostly likely be spiritually fruitful. Pope Emeritus Benedict once said of the Divine Office that, “I would like to renew to you all the invitation to pray with the Psalms, even becoming accustomed to using the Liturgy of the Hours of the Church, Lauds in the morning, Vespers in the evening, and Compline before retiring. Our relationship with God cannot but be enriched with greater joy and trust in the daily journey towards Him.”
 Second Vatican Council. Sacrosanctum Concilium [Constitution on the Sacred Liturgy], sec. 84-85. Vatican Website, accessed December 22, 2016, http://www.vatican.va/archive/hist_councils/ii_vatican_council/documents/vat-ii_const_19631204_sacrosanctum-concilium_en.html.↩
 Sacrosanctum Concilium, Art. 98.↩
 Catechism of the Catholic Church, Art. 1174. Vatican Website, accessed December 22, 2016, http://www.vatican.va/archive/ENG0015/__P39.HTM.↩
 Pope Benedict XVI. Summorum Pontificum [Apostolic Letter on the use of the Roman liturgy prior to the reform of 1970 given Motu Propio], Art. 9 § 3. Vatican Website. July 7, 2007, accessed December 22, 2016, http://w2.vatican.va/content/benedict-xvi/en/motu_proprio/documents/hf_ben-xvi_motu-proprio_20070707_summorum-pontificum.html.↩
 Offices of the Pontifical Commission. Ecclesia Dei. Universae Ecclesiae [Instruction on the application of the Apostolic Letter Summorum Pontificum of His Holiness Benedict XVI given Motu Propio], Art. 34. Vatican Website. April 30, 2011, accessed December 22, 2016, http://www.vatican.va/roman_curia/pontifical_commissions/ecclsdei/documents/rc_com_ecclsdei_doc_20110430_istr-universae-ecclesiae_en.html.↩
 Pope Benedict XVI. General Audience, St. Peter’s Square. Vatican Website. November 16, 2011, accessed December 22, 2016, https://w2.vatican.va/content/benedict-xvi/en/audiences/2011/documents/hf_ben-xvi_aud_20111116.html.↩