St. Bonaventure (1221-1274)

Bonaventure, Franciscan, theologian, doctor of the Church, was both learned and holy. Because of the spirit that filled him and his writings, he was at first called the Devout Doctor; but in more recent centuries he has been known as the Seraphic Doctor after the "Seraphic Father" Francis because of the truly Franciscan spirit he possessed.

Born in Bagnoregio, a town in central Italy, he was cured of a serious illness as a boy through the prayers of Francis of Assisi. Later, he studied the liberal arts in Paris. Inspired by Francis and the example of the friars, especially of his master in theology, Alexander of Hales, he entered the Franciscan Order, and became in turn a teacher of theology in the university. Chosen as minister general of the Order in 1257, he was God's instrument in bringing it back to a deeper love of the way of St. Francis, both through the life of Francis which he wrote at the behest of the brothers and through other works which defended the Order or explained its ideals and way of life.

Bonaventure so united holiness and theological knowledge that he rose to the heights of mysticism while yet remaining a very active preacher and teacher, one beloved by all who met him. To know him was to love him; to read him is still for us today to meet a true Franciscan and a gentleman.

from: St. Bonaventure - Saint of the Day - American Catholic

And so theology is the only perfect science, for it begins at the beginning which is the first Principle, and proceeds to the end, which is the final wages paid; it begins with the summit, which is God most high, the Creator of all, and reaches even to the abyss, which is the torment of hell.

Bonaventure, Breviloquium I:1:2, with thanks to A Minor Friar, whose whole post is very well worth reading.

Much, much more about the Seraphic Doctor can be found at the Franciscan Archive, here, including online texts of his writings, in Latin, English, French and Spanish. Superb resource!