Christian mysticism in the context of "O.S.B."

Hildegard of Bingen OSB (German: Hildegard von Bingen, pronounced [ˈhɪldəɡaʁt fɔn ˈbɪŋən]; Latin: Hildegardis Bingensis; c. 1098 – 17 September 1179), also known as the Sibyl of the Rhine, was a German Benedictine abbess and polymath active as a writer, composer, philosopher, mystic, visionary, and as a medical writer and practitioner during the High Middle Ages. She is one of the best-known composers of sacred monophony, as well as the most recorded in modern history. She has been considered by a number of scholars to be the founder of scientific natural history in Germany.

Hildegard's convent at Disibodenberg elected her as magistra (mother superior) in 1136. She founded the monasteries of Rupertsberg in 1150 and Eibingen in 1165. Hildegard wrote theological, botanical, and medicinal works, as well as letters, hymns, and antiphons for the liturgy. She wrote poems, and supervised miniature illuminations in the Rupertsberg manuscript of her first work, Scivias. There are more surviving chants by Hildegard than by any other composer from the entire Middle Ages, and she is one of the few known composers to have written both the music and the words. One of her works, the Ordo Virtutum, is an early example of liturgical drama and arguably the oldest surviving morality play. She is noted for the invention of a constructed language known as Lingua Ignota.

Caterina di Jacopo di Benincasa (25 March 1347 – 29 April 1380), known as Catherine of Siena, was an Italian mystic and pious laywoman who engaged in papal and Italian politics through extensive letter-writing and advocacy. Canonized in 1461, she is revered as a saint and as a Doctor of the Church due to her extensive theological authorship. She is also considered to have influenced Italian literature.

Born and raised in Siena, Catherine wanted from an early age to devote herself to God, against the will of her parents. She joined the "mantellates", a group of pious women, primarily widows, informally devoted to Dominican spirituality; later these types of urban pious groups would be formalized as the Third Order of the Dominicans, but not until after Catherine's death. Her influence with Pope Gregory XI played a role in his 1376 decision to leave Avignon for Rome. The Pope then sent Catherine to negotiate peace with the Florentine Republic. After Gregory XI's death (March 1378) and the conclusion of peace (July 1378), she returned to Siena. She dictated to secretaries her set of spiritual treatises, The Dialogue of Divine Providence. The Great Schism of the West led Catherine of Siena to go to Rome with the pope. She sent numerous letters to princes and cardinals to promote obedience to Pope Urban VI and to defend what she calls the "vessel of the Church". She died on 29 April 1380, exhausted by her rigorous fasting. Urban VI celebrated her funeral and burial in the Basilica of Santa Maria sopra Minerva in Rome.

The Most Sacred Heart of Jesus (Latin: Cor Jesu Sacratissimum) is one of the most widely practised and well-known Catholic devotions, wherein the heart of Jesus Christ is viewed as a symbol of "God's boundless and passionate love for mankind". This devotion to Christ is predominantly used in the Catholic Church, followed by high church Anglicans, and some Western Rite Orthodox. In the Latin Church, the liturgical Solemnity of the Most Sacred Heart of Jesus is celebrated on the third Friday after Pentecost. The 12 promises of the Most Sacred Heart of Jesus are also popular.

The devotion is especially concerned with what the church deems to be the long-suffering love and compassion of the heart of Christ towards humanity. The popularization of this devotion in its modern form is derived from a Roman Catholic nun from France, Margaret Mary Alacoque, who said she learned the devotion from Jesus during a series of apparitions to her between 1673 and 1675, and later, in the 19th century, from the mystical revelations of another Catholic nun in Portugal, Mary of the Divine Heart, a religious sister of the congregation of the Good Shepherd, who requested in the name of Christ that Pope Leo XIII consecrate the entire world to the Sacred Heart of Jesus. Predecessors to the modern devotion arose unmistakably in the Middle Ages in various facets of Catholic mysticism, particularly with Gertrude the Great.

Karen Armstrong (born 14 November 1944) is a British author and commentator known for her books on comparative religion. A former Roman Catholic religious sister, she went from a conservative to a more liberal and mystical Christian faith. She attended St Anne's College, Oxford, while in the convent and graduated in English. She left the convent in 1969. Her work focuses on commonalities of the major religions, such as the importance of compassion and the Golden Rule.

Armstrong received the US$100,000 TED Prize in February 2008. She used that occasion to call for the creation of a Charter for Compassion, which was unveiled the following year.

Tristan und Isolde (Tristan and Isolde), WWV 90, is a music drama in three acts by Richard Wagner set to a German libretto by the composer, loosely based on the medieval 12th-century romance Tristan and Iseult by Gottfried von Strassburg. First conceived in 1854, the music was composed between 1857 and 1859 and premiered at the Königliches Hoftheater und Nationaltheater in Munich on 10 June 1865 with Hans von Bülow conducting. While performed by opera companies, Wagner preferred the term Handlung (German for "plot" or "action") for Tristan to distinguish its structure of continuous narrative flow ("endless melody") as distinct from that of conventional opera at the time which was constructed of mundane recitatives punctuated by showpiece arias, which Wagner had come to regard with great disdain.

Wagner's composition of Tristan und Isolde was inspired in part by the philosophy of Arthur Schopenhauer, as well as by his relationship with his muse Mathilde Wesendonck. The opera, which explores existential themes such as that of mankind's insatiable striving and the transcendental nature of a love beyond death, incorporates spirituality from Christian mysticism as well as Vedantic and Buddhist metaphysics, subjects that also interested Schopenhauer. As such, Wagner was one of the earliest Western artists to introduce concepts from the Dharmic religions into their works.