He was born at
Dorpat (today Tartu) in
Livonia (then a province of
Russia, now in
Estonia) where his father,
Theodosius Harnack, held a professorship of
pastoral theology. He was the twin brother of
Carl Gustav Axel Harnack. He married Amalie Thiersch on 27 December 1879. Their daughter
Agnes von Zahn-Harnack became an activist in the
Women's movement. Harnack studied at the local
Imperial University of Dorpat (1869–72) and at the
University of Leipzig, where he took his degree; soon afterwards, in 1874, he began lecturing as a
Privatdozent. These lectures, which dealt with such special subjects as
Gnosticism and the
Apocalypse, attracted considerable attention, and in 1876 he was appointed
professor extraordinarius. In the same year he began the publication, in conjunction with
Oscar Leopold von Gebhardt and
Theodor Zahn, of an edition of the works of the
Apostolic Fathers,
Patrum apostolicorum opera, a smaller edition of which appeared in 1877. In 1879 he was called to the
University of Giessen as
professor ordinarius of
church history. There he collaborated with Gebhardt in
Texte und Untersuchungen zur Geschichte der altchristlichen Litteratur (1882 sqq.), an irregular
periodical, containing only essays in
New Testament and
patristic fields. In 1881 he published a work on
monasticism,
Das Mönchtum – seine Ideale und seine Geschichte (5th ed., 1900; English translation, 1901), and became joint editor with
Emil Schürer of the
Theologische Literaturzeitung. In 1885 he published the first volume of his
Lehrbuch der Dogmengeschichte (3rd ed. in three volumes, 1894–1898; English translation in seven volumes, 1894–1899). In this work Harnack traced the rise of
dogma, which he understood as the authoritative
doctrinal system of the church and its development from the 4th century down to the
Protestant Reformation. He considered that from its earliest origins, Christian faith and Greek philosophy were so closely intermingled that the resultant system included many beliefs and practices that were not authentically Christian. Therefore,
Protestants are not only free, but bound, to criticize it; Protestantism could be understood as a rejection of this
dogma and a return to the pure faith that characterized the original church. An abridgment of this appeared in 1889 with the title
Grundriss der Dogmengeschichte (3rd ed., 1898). In 1886 Harnack was called to the
University of Marburg and in 1888, in spite of violent opposition from the conservative church authorities, to Berlin. In 1890 he became a member of the Academy of Sciences. In Berlin, somewhat against his will, he was drawn into a controversy on the
Apostles' Creed, in which the partisan antagonisms within the
Prussian Church had found expression. Harnack's view was that the creed contains both too much and too little to be a satisfactory test for candidates for
ordination; he preferred a briefer declaration of faith which could be rigorously applied to all (cf. his
Das Apostolische Glaubensbekenntnis. Ein geschichtlicher Bericht nebst einer Einleitung und einem Nachwort, 1892). In Berlin, Harnack continued writing. In 1893 he published a history of
early Christian literature down to
Eusebius of Caesarea,
Geschichte der altkirchlichen Literatur bis Eusebius (part 2 of vol. 5., 1897); and in his popular lectures,
Das Wesen des Christentums appeared in 1900 (5th ed., 1901; English translation,
What is Christianity? 1901). One of his later historical works,
Die Mission und Ausbreitung des Christentums in den ersten drei Jahrhunderten (1902; English translation,
The Mission and Expansion of Christianity in the First Three Centuries, in two volumes, 1904–1905), was followed by some important
New Testament studies (
Beitrage zur Einleitung in das neue Testament, 1906 sqq.; Engl. trans.:
Luke the Physician, 1907;
The Sayings of Jesus, 1908). on the occasion of the inauguration of a new
Kaiser-Wilhelm-Institut (1913). Harnack was one of the most prolific and stimulating of modern critical scholars, and brought up in his "Seminar" a whole generation of teachers who carried his ideas and methods throughout the whole of Germany and beyond. From 1905 to 1921, Harnack was the General Director of the
Royal Library at Berlin (from 1918 called the Prussian State Library). Like many liberal professors in Germany, Harnack welcomed
World War I in 1914, and signed a public statement endorsing Germany's war-aims (the
Manifesto of the Ninety-Three). It was this statement, with his teacher Harnack's signature on it, that
Karl Barth cited as a major impetus for his rejection of liberal theology. Harnack was one of the moving spirits in the foundation, in 1911, of the Kaiser Wilhelm Gesellschaft (KWG), and became its first President. The Society's activities were much constrained by the First World War, but in the
Weimar Republic period Harnack guided it to be a major vehicle for overcoming the isolation of German academics felt as a result of the war and its aftermath. The society's flagship conference centre in Berlin, the
Harnack House, which opened in 1929, was named in his honour. After a long period in
U.S. Army hands after
World War II it has now resumed the role Harnack envisaged, as a centre for international intellectual life in the German capital, under the management of the KWG's successor organisation, the
Max Planck Gesellschaft. ==Biblical Criticism and Theology==