In Oxford he was allowed to hold a disputation with some learned doctors on the rival merits of the Copernican and so-called Aristotelian systems of the universe, and, according to his own report, had an easy victory.
Lecturing on Isaiah he condemned current ecclesiastical abuses, and in a public disputation (loth of August 1523) was so successful that Erasmus writing to Zurich said "Oecolampadius has the upper hand amongst us."
He hid himself in the Dominican convent at Leipzig in fear of popular violence, and died there on the 4th of July 1519, just as Luther was beginning his famous disputation with Eck.
Its immediate occasion was the disputation at Heidelberg (1568) for the doctorate of theology by George Wither or Withers, an English Puritan (subsequently archdeacon of Colchester), silenced (1565) at Bury St Edmunds by Archbishop Parker.
Withers had proposed a disputation against vestments, which the university would not allow; his thesis affirming the excommunicating power of the presbytery was sustained.