This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Harnack's What Is Christianity? marked the turn of the century height of Liberal Theology's confidence in historical criticism, a documented peak that the very confidence Karl Barth and the Neo-Orthodox theologians reacted against after the First World War is recorded as targeting directly. That reaction is documented as arriving after Harnack's own lectures rather than alongside them, a later movement answering a confidence already at its most visible expression rather than one theological camp arguing against another from the start.
Beyond theology, Harnack was the first president of the Kaiser Wilhelm Society, a documented leadership role in scientific administration distinct from his work as a historian of dogma and Berlin professor, later renamed the Max Planck Society in a tradition of scientific leadership his own presidency is credited with beginning. That a Protestant theologian best known for reducing Christianity to three themes also stood at the head of Germany's leading scientific research organization is documented as two separate careers held by the same man rather than one activity extending into the other.
That the theologian whose 1900 lectures marked Liberal Theology's confident peak also led Germany's foremost scientific society, and that the same peak drew the Neo-Orthodox reaction that followed the First World War, marks Harnack's combined legacy as a documented case where one figure's influence crested in theology and science together just before a new theological generation turned against the confidence that had produced it.