Locke, who defended the doctrine of immortality (Phädon, 1767) and the existence of God (Morgenstunden, 1786) on rational grounds, exerted a profound influence on the worldly classes. Mendelssohn is convinced that the dogmatics of Judaism contain nothing which transcends natural religion (Jerusalem, 1783). Many Protestant theologians likewise held similar views with reference to Christianity. It was only in exceptional and isolated cases that the relation between natural and positive religion became more hostile. Thus, for example, J. Chr. Edelmann (1698-1767), who has given an interesting account of his doctrinal evolution in his Autobiography (published 1849), passed from orthodoxy to pietism and finally to a Spinozistic type of rationalism. He translated "Logos" at the beginning of the Gospel of John "Reason," and, like Spinoza, he regarded God only as the immanent, not as the transcendent cause of the world. The only way in which he could find true religiosity in the biblical writings was by historical criticism and symbolic interpretation. Professor Reimarus (1694-1768) of Hamburg, the author of the Wolfenbüttel Fragments published by Lessing, was unable to conceive this relation so simply and harmoniously. He thinks that the human understanding and conscience are in irreconcilable conflict with the content of the Scriptures. Revelation is a physical and moral impossibility. The only possible explanation of the origin of the biblical traditions is on the hypothesis of a series of self-deceptions.
The German philosophy of the enlightenment did not confine itself to psychology and the philosophy of religion, but was likewise active in the department of epistemology. C. A. Crusius (1712-1775) showed that the distinction between sense-perception and pure thought is not identical