St. Bernard of Clairvaux is a Doctor of the Church and Abbot. He was born in the castle of Fontaines des Dijon, in France, the son of Tescelin Sorrel and Aleth de Montbard; he was the third son in a family of seven children. Aleth’s death influenced him deeply so that about age seventeen he left the school of Chatillon-sur-Seine and in 1113 entered the monastery of Citeaux, which had been founded in 1098 and was under the brilliant leadership of the abbot St. Stephen Harding. He persuaded his four brothers and twenty-seven other relatives and friends also to enter the Cistercian monastery.

Bernard threw himself into the rigorous austerity of the community, declaring that he was “conscious of the need of my weak nature for strong medicine.” His devotion to mortification, however, caused severe problems of health, especially as he had a weak constitution. Illness, aggravated by stern ascetic practices, would plague him for the rest of his life.

At Citeaux, Bernard came under the instruction of the remarkable Abbot Stephen Harding, who in 1115 chose him with twelve monks to found a monastery at Langres. He chose Clairvaux, which was granted a charter by Pope Callistus II in 1119 and became the motherhouse of sixty-eight Cistercian abbeys. As his reputation for scholarship and holiness spread, Bernard was consulted by popes and monarchs. In 1128 he was secretary to the Synod of Troyes; in 1130, he assisted Pope Innocent II in overcoming the threat of antipope Anicletus; and he preached tirelessly against heresies and to gather support for the Second Crusade. In defending Church orthodoxy, he spoke out against the onetime monk Henry of Lausanne and, most notably, against Peter Abelard, whose condemnation he secured in 1140 at the Council of Sens. In that same year, Bernard convinced the people of Lombardy to accept Lothair III as emperor. In 1148 he condemned the writings of the theologian Gilbert de la Porree.

In 1142, Bernard witnessed the coronation of one off his postulants, Bernardo Pignatelli, as Pope Eugene III, authoring for his former student the treatise De Consideratione, and some of the difficulties he could anticipate. This pope sent Bernard to Languedoc, in southern France, to convert the local members of the Albigensian heresy. In 1146, he preached against Rhineland-area pogroms and also supported the Second Crusade and King Louis VII of France. The crusade ended in disaster and was a deep disappointment to Bernard. In 1153, he settled another political dispute but was taken ill shortly after. He died at Clairvaux on August 20. Considered by many to be the second founder of the Cistercians, he dominated religious and political affairs in Western Europe.

His mystical writings include de Diligendo Dei, which laid the foundation for medieval mysticism. His commentary on the Song of Songs, his Treatise on the Love of God, and his De Consideratione are considered treasures of the faith. More than three hundred sermons were recorded, as well as five hundred letters, all demonstrating his devotion to the Blessed Virgin Mary and the infant Jesus. For his brilliance and contributions to theology he was called “the Mellifluous Doctor.” St. Bernard of Clairvaus is declared a Doctor of the Church which are certain men and women who are revered by the Church for the special value of their writings and preaching and the sanctity of their lives. They each made important and lasting contributions to the faith and are to be recognized for their great merits.

To be declared a Doctor of the Church, you have to meet three basic requirements:

1. First, you must have lived a life of exemplary holiness, or insignis vitae sanctitas (outstanding sanctity). In short, you have to be a saint.
   

2. Second, to be a Doctor of the Church you must have deepened the whole Church's understanding of the Catholic Faith with emins doctrina (eminent teaching). Which is to say, sanctity isn't enough. There are thousands of saints, but only 37 Doctors of the Church. To be a Doctor one must do more than just live the Faith. Rather, one must significantly and profoundly contribute to our understanding of Divine Revelation, helping us to know more deeply some truth about God and His actions in the World.
   

3. And third, a pope must officially declare you a Doctor. That being said, as the Church understands it, when a pope declares someone a Doctor of the Church, he's not so much making someone a Doctor as he is recognizing what the Holy Spirit has already done - that He has conferred the charism of Doctor upon them.