He was additionally Abbot-elect of Newbattle, Abbot of Dundrennan, nominal Bishop of Dunkeld, and also held the Abbey of Coupar Angus in commendam.
While remaining a Newbattle monk, the following year Thomas entered the University of Cologne in order to become a Master of Theology, which he attained in 1425.
Although conciliarism looked doomed by the early 1440s, Thomas nevertheless remained an ardent conciliarist, and helped shape Scottish politics as an adviser during the minority of King James II of Scotland.
In 1447 Pope Eugene died, and Livingston was one of the two Basel delegates who went to Vienna to attempt to persuade Frederick III, Holy Roman Emperor to convoke a new council of the church.
After the schism caused by the election of Antipope Felix V was finally healed in 1447, the blind Livingston turned his attention to promoting monastic reform, working alongside Cardinal Nikolaus von Kues (a friend of his from university) in the latter's mission in Germany (1451-2).