What is one way that historians can establish the authenticity of a primary source

Is karma the same as destiny, in the sense that everything that happens to you is predetermined? do you believe that "what goes around comes around," and if so is this the same as karma? does everyone get what they deserve, in the end?

Where were the trials to review evidence in cases against high-ranking nazi officials accused of war crimes held?

Which concept is plato expressing in the excerpt below? when men have both done and suffered tyranny, and have had experience of both . . they think that they had better agree among themselves to have neither. . —plato, the republic: book ii