To his contemporaries, Odo of Tournai--master of the cathedral school of Tournai, first abbot of the restored monastery of St. Martin of Tournai, and, later, Bishop of Cambrai--was one of the most illustrious teachers and philosophers in Christendom. Yet only one of his works, a treatise on the Mass, has heretofore been translated into English. Irven M. Resnick here provides the first English-language translation of two of Odo's other works. The first, On Original Sin, is at once an exposition of Christian doctrine and a philosophical investigation into the origin of the soul, the character of the sin that all human beings inherit from Adam, and the relationship of the individual to the species. The second translated text, A Disputation with the Jew, Leo, Concerning the Advent of Christ, the Son of God, continues the discussion, in dialogue form, of original sin and its effects.