This article deals with two schools of Mull Sadr ‘s Transcendent Theosophy and J?spers existentialism . In this study, one should take. heed of the terminology of both schools in studying their problems and solutions, of course, the two schools are of two differing histories and traditions, yet both of them emphasize the knowledge of man and refer to a central core in the definition of man as existence or soul which cannot be defined due to their dynamism, perceptual nature, and freedom. This fact possesses innumerable branches and offshoots and basically man does not enjoy a predetermined entity and each individual is unique in and of himself. In Sadr ‘s school of thought the body and soul are deeply interwoven. The body is the lower level of the soul, and the soul is the developed realization of the body. In J?spers ‘s opinion man has different aspects: Dasein, knowledge at large, spirit, and existence, which arc all interacting with one another. In the eyes of both thinkers, man has various aspects. Nevertheless, in order to know him, one should pay special attention to his soul and its related aspects. Both thinkers have identified three realms in man’s soul that are rated as soul functions and knowledge of them assists in knowing the soul better.
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