For over a generation now (in Protestant circles) natural theology has fallen on evil days. Barth has stamped ruthlessly on every attempt to ground the Christian faith in any form of general knowledge. ‘Back to the biblical faith’ became his watchword. Bultmann likewise scorned Weltanschauung as the importation of Stoicism into the non-philosophical Christian faith. Between Barth's biblical theology and Bultmann's existentialism there was such a strong bond of common hostility to general revelation that natural theology was rejected outright—for natural theology is most properly defined as any knowledge of God, His will and His ways, based on man's general experience, knowledge, and reason.
Lately, however, for good or ill, there are some signs of return. The thrust of Kierkegaard's anti-rational and antiempirical polemic is being broken both as its newness wears off and as its negativity stands naked before us. The anti-theological as well as the an ti-metaphysical drive of linguistic philosophy is slowing down, and there is even evident most recently a somewhat more constructive mood and method within this philosophical position. The power of Tillich's position, in sharp contrast, has been partly due to a bold system holding that, while recognising the truths inherent in both Barth's anti-liberal stand and Bultmann's existential interpretation of the Christian faith, nevertheless dares to base itself on the fulness of the facts of experience and of human history. Tillich's positive and inclusive approach is commending itself to a fast expanding circle of thinkers.