Seeking to establish for himself a middle position between rationalism and supernaturalism, he declared for a "rational supernaturalism," and contended that there must be a gradual development of Christian doctrine corresponding to the advance of knowledge and science. But at the same time he sought, like other representatives of this school of thought, such as KG Bretschneider and Julius Wegscheider, to keep in close touch with the historical theology of the Protestant churches.
He was a man of great versatility and extensive learning, a philologist and philosopher as well as a theologian, and a very voluminous author. His principal theological work was the Fortbildung des Christenthums zur Weltreligion, in 4 volumes (Leipzig, 1833–1840); Entwurf einer reinbiblischen Theologie appeared in 1792 (2nd ed., 1801), Summa Theologiae Christianas in 1803 (other editions, 1808, 1816, 1830); Das Leben Jesu in 1842, and Die wahre und falsche Orthodoxie in 1849.
Von Ammon's style in preaching was terse and lively, and some of his discourses are regarded as models of pulpit treatment of political questions.