As a youth, he was interested in music and poetry, and was attracted by ancient and German classical literature, especially by Jean Paul.
[1] Harless wanted to understand the reasons for the importance of the Christian religion in the life of the people and the history of the world.
Harless received a further impulse from his study of Blaise Pascal's Pensées, but at about this time he had a crisis of conscience; he turned to the confessional writings of the Lutheran Church and found their contents in conformity with the experience of his faith.
In 1840 he was appointed delegate of the chamber of states in Munich to defend the rights of the Lutheran Church against the measures of the ministry.
Harless won popularity by defending the interests of his church but the opposition party succeeded in removing him in 1845 to Baireuth, as second councilor of the consistory.
Here Wilhelm Löhe and his adherents opposed the existing condition of the State Church, and insisted on an entire change, or, if this should be impossible, on separation.
The encyclopedia is less important for its methodological arrangement than for Harless' clear and energetic views of the Church, the main points being the close relation of theology to the Church; the unity of theory and practise in a common living faith; the living continuity of the Church from her very foundation as an ideal factor of history, the emphasis of a common faith as the basis of Protestant theology; the entire transformation of this theology by the principle of justification; the necessity of preserving the principles of the Reformation in their purity; the obscurity caused by the later Protestant scholasticism, which considered the dogmas laid down in the confessional writings of the Church as the final conclusion of all dogmatic knowledge; and the sound reaction against this tendency by the Pietistic movement.
[3] He died on 5 September 1879, having, a few years earlier, written an autobiography under the title Bruchstücke aus dem Leben eines süddeutschen Theologen.