It is common to refer to these various branches of Carmel under the general heading of "The Carmelite Order", though technically the "Carmelite Order" is the Ancient Observance and other groups are autonimous congregations. Since they share a uniting spirit or 'charism' they are often grouped together under the term "The Carmelite Family", and we speak of one family consisting of various branches. The two main branches are the 'Ancient' and 'Teresian' Observances. They share much in essence, and really differ only in small matters of emphasis.
The Ancient Observance
The oldest continuous branch of the Carmelite Family is sometimes referred to as the 'Ancient Observance'. It is the original 'Carmelite Order', abbreviated as "O.Carm.". The term 'Calced Carmelites' (to distinguish from the 'Discalced Carmelites') is not actually used by the Ancient Observance itself.
The British Province of Carmelites is part of the Ancient Observance.
The crest of the Ancient Observance of the Carmelite Order is usually shown without a cross at the summit of the mountain.
The Discalced Observance
The crest of the Discalced Carmelites is exactly the same as that of the Carmelites (O.Carm.), with the addition of a cross at the summit of the mountain. This version of the crest is often associated with reform movements within Carmel. It was first used within the Carmelite Order (O.Carm.), and is sometimes still used by the Ancient Observance, but generally it is associated with the Discalced Carmelites.
Examples include the Carmelites of Mary Immaculate (the CMIs) who are very active in India, and were originally an off-shoot of the Discalced Carmelites. In Britain there are the Carmelite Missionary Sisters in London. In America there are communities such as the Carmelite Monks in Wyoming who represent a new innovation (historically Carmelite men were hermits or friars, but only the women were monastic).
When people ask "What is the difference between the different observances?", it is sometimes hard to give a precise answer. In essence their spirituality is the same, with slightly different emphases (for example, the Discalced Carmelites would stress the teachings of St. Teresa whereas the Ancient Observance would reflect more regularly on the figure of Elijah, though both are important in each tradition). When discerning which 'branch' of the Family to belong to, it is usually a question of a candidate deciding where he or she feels most at home. Whatever branch a candidate opts for, his or her formation will almost certainly include contact with the whole breadth of the Carmelite Family, including both the major branches.
Division and unity within the Carmelite Family
The following information comes from Johan Bergström-Allen, (ed.), Climbing the Mountain: The Carmelite Journey, (Faversham & Rome: Saint Albert's Press & Edizioni Carmelitane, 2010), pp. 176-78.
Carmel has a long tradition of reform movements, all working as part of the Order to bring about renewal from within. The Discalced reform began in this way, but soon the movement caused division amongst the friars and sisters which wasn't helped by the outside intervention of Church and Civil authorities. Attaching themselves to Teresa's reform movement and using the protection of the Spanish court, a number of friars from the province of Andalusia rebelled against the Prior General and the heavy-handed Carmelite superiors in Spain. Each side of the debate held visitations (inspection tours of the provinces) and chapters (meetings) that the other declared invalid. The Papacy, the King of Spain, and other religious orders (notably the recently-formed Jesuits) became embroiled in the debate. The Carmelite friars of the Discalced movement were led by the charismatic Jerome Gracián (1545-1614). Teresa was deeply saddened by the divisions growing within Carmel.
During Teresa's later life (and after her death), disputes continued within the Carmelite Order about the way in which the Discalced Reform should be governed. An upshot of this dispute in 1577 was the removal of Brother John of the Cross from his house near The Incarnation Monastery. He was placed in prison (commonly found in Carmelite houses at that time for the detention of wayward friars!), where he remained until his escape in August 1578. During this time, he wrote a number of poems including most of The Spiritual Canticle and The Dark Night.
Despite Teresa's desire for unity within the Order (she was friends with both Gracián and the Prior General), the political strains were too much and the Discalced movement asked for independence from the Carmelite Order. Within a decade and a half of the death of the Prior General John Baptist Rossi in 1578 there were effectively two autonomous branches of the Carmelite Family in Spain, each recognised as independent by the Papacy: the Carmelites ('O.Carm.', sometimes called the 'Ancient Observance' to distinguish them from the Discalced), and the Discalced Carmelites ('O.C.D.'). Eventually the Discalced Reform itself split between its Spanish and Italian congregations.
It is said that history is written by the victors, but in the case of the split in our family it is hard to see whether anyone won! Both sides of 'the divide' have traditionally interpreted the Spanish reform differently, and this has sometimes led to painful distrust on both sides, although there have been many examples of close collaboration between the two branches of the Order since the very first days of their formal division. In the Ancient Observance Teresa is regarded as one of the great saints of Carmel, and as our sister. In the Discalced Carmelite Order it is traditional to refer to Teresa as 'La Madre' ('our holy mother'), and until relatively recently many Discalced Carmelites regarded her as not only the founder of the Teresian Reform, but indeed the forunder of 'the true Carmel'. However, this is changing, and as James McCaffrey, O.C.D., observes in his book The Carmelite Charism, Teresa and John did not found a new Order but rather reformed a three hundred year-old tradition that traces its roots back (at least spiritually) to Elijah and Mary, and the first Carmelites in the Holy Land.
The result of the protagonists' unwillingness to listen to the other parts of the Carmelite Family - a fault on both sides - has been that traditionally many Discalced Carmelites have tended not to know very much about the three hundred years of Carmelite spirituality and history before Teresa, and tend to read Carmelite history through the eyes of Teresa and John. On the other hand, some Carmelites (O.Carm.) have been slow in appreciating all there is to learn from the great saints of the Discalced tradition, not only Teresa and John but also later saints such as Lawrence of the Resurrection, Elizabeth of the Trinity, and Edith Stein. There has also been a mutual suspicion that Discalced Carmelites are more given over to prayer and asceticism whilst Carmelites of the Ancient Observance are more given over to the active apostolate. Today most accept that these are false distinctions and caricatures based on prejudice.
Thanks to the call of the Second Vatican Council for religious orders to return to their roots, both branches of the Carmelite Family have been united in their renewed appreciation of the Rule of Saint Albert as the text that unites all Carmelites, and equally committed to the honest reappraisal of Carmelite history. Since the 1970s regular talks have taken place across the Carmelite Family at every level. Of particular note are the discussions between the Prior General (O.Carm.) and the Prepositus General (O.C.D.), and the letters they have issued together since 1992 (printed in the collection In obsequio Jesu Christi). Also beneficial have been the Carmelite Forums and Institutes established in various parts of the world, and other joint projects and formation programmes. We also share a common liturgical calendar (with slight variations). It has become clear that we must collaborate and recognise each others' gifts, and that what divides the traditions is tiny in proportion to what we share.
The Carmelite Family has tended to follow the pattern of most divided communities, as seen in places like the north of Ireland and the different denominations of the Church: first the different sides argue and the tension becomes so great that the community splits; then there is a period of not talking to each other when ignorance feeds prejudices; then we wake up to the scandal of division and our hearts are touched to begin polite communication, before we get down to debating our differences in a frank but mature and respectful fashion; finally, either unity is achieved, or we learn to celebrate the different gifts that each group brings to being Carmelites.
Some people would like to see the two branches of the Carmelite Family formally reunited, whilst others believe that something distinctive would be lost from either Order; they say that just as a rainbow is one entity consisting of many colours, so being united doesn't mean that we all have to be the same. Today most people recognise that there is only one Carmelite charism but that it is lived distinctively in two orders (and indeed in several other independent congregations that have developed in recent centuries, such as the Carmelites of Mary Immaculate, largely based in India). In terms of terminology, some speak of the one 'Carmelite Order' consisting of two or more branches; others speak of 'The Carmelite Order' and 'The Discalced Carmelite Order' as two separate orders but sharing a common heritage.