The origin of Campbell's scholarly career can be traced back to his years at the parish. He established himself as a scripture critic, and lecturer of holy writ. Campbell began his lifelong ambition of translating the gospels, and around 1750, he composed the first two chapters of "The Philosophy of Rhetoric". Campbell's growing reputation impressed the magistrates of the city of Aberdeen and he was offered a ministerial position in 1757. His return brought him to the core of the growing intellectual community in northeast Scotland. In 1759, Campbell was offered the position of principal at Marischal College and he fully immersed himself in university affairs.