Andrei Tikhomirov - Philosophical Notes. Learning the world through philosophy стр 5.

In the Upanishads, primarily in the works mentioned above, an attempt is made to pose and discuss such significant philosophical problems as clarifying the fundamental principles of nature and man, the nature of man, his place and role in his environment, cognitive abilities, norms of behavior and role in this human psyche. Of course, the interpretation and explanation of all these problems is very controversial, and sometimes there are opinions that are mutually exclusive.