In 1829 he was made professor at the university of Berlin.

Ten years later he was made professor of sociology and economics at the same university.

He was made full professor in 1988, and remained at Maryknoll until 1995.

In 1890, he was made Professor in these same subjects.

Six years later he was made clinical professor at the Mem.

The following year he was made professor of English, a position he retained through the 1860s and 1870s.

In 1952 he was made assistant professor at the University of Toronto.

On January 4, 1887, he was made assistant professor at that university, then in 1899, full professor.

Six years after his return to Yale he was made professor of Latin.

He was promoted to reader in 1946 and made Professor in 1947.