Reference Notices:
The Universal Jewish Encyclopedia (1940)

Brunner, Constantin (originally Leopold Wertheimer), philosopher, b. Altona, Germany, 1862; d. The Hague, 1937. The grandson of chief rabbi Akiba Wertheimer of Altona, he lived in Potsdam until the advent of the Nazi party, when he removed to The Hague.
In the essence of their thought and philosophical conclusions his doctrines are related to Spinozaís system. He is opposed to Kant and to all epistemology. Brunnerís philosophy is based on his theory of the faculties. He distinguished three faculties or possibilities of thinking, as follows: 1. Practical understanding, possessed in common by all human beings (i.e. the sum total of feeling, knowing and willing, or, to put it simply, egoism); 2. The intellect, possessed by the few, which manifests itself productively and reproductively in art, philosophy and mysticism; 3. Superstition, common to the may, which expresses itself in religion, metaphysics, and morals.
Brunner bases his theory of motion on his conceptions of the nature of substance and of motion; on this theory he bases his psychology. He endeavors to bring clearness and certainty in the conduct of life through insight into the universality and general validity of egoism. But it is his supreme aim to awaken, by means of his doctrine of the intellect, an inclination towards unity and eternity in those naturally capable of such an inclination. Proceeding from his doctrine of egoism, he arrives at new conclusions regarding the structure of human society, state and nation. From these points of view he resolutely combats Zionism. However, he attaches great importance to the idea of Judaism which he believes was represented in its purest form by Jesus; he advances this idea very strongly.