Harnack

Harnack is a German surname that has appeared in a number of scholarly and cultural contexts. It is associated with notable individuals in theology, mathematics, and related fields, and with institutions named after them.

Adolf von Harnack (1851–1930) was a prominent German theologian and church historian whose critical study of early Christianity influenced Protestant theology and biblical scholarship. His writings helped shape modern approaches to the history of the Christian church and its documents.

Axel Harnack (1863–1928) was a German mathematician known for work in analysis and geometry. The best-known result bearing his name is Harnack's inequality, a fundamental tool in the theory of positive harmonic functions that provides bounds within a domain and underpins several regularity results in potential theory and partial differential equations. The concept of Harnack’s principle and related ideas are also associated with his contributions.

Harnack House (Haus Harnack) is a historic guesthouse and conference facility in Berlin named in honor of Adolf von Harnack. It is affiliated with scholarly activities and used by researchers and visiting scholars, notably in connection with the Alexander von Humboldt Foundation.