A knowledge of history, literature, and psychology can help one penetrate the many layers of conditioning to which we are subject and can help one understand what the collective unconscious is working through -- what conclusions it has reached, unbeknownst to itself. This is different than conspiracy theory. For example, I can go see "Schindler's List" and realize that it is not a movie about World War II, though it finds it useful as a symbolic coordinate. What the movie is really about is the present. What it really argues is that in the present intellectuals are more valuable than workers; we are all lucky to have a job; we all have two choices: psychotic capitalism or rational capitalism. I can go see "Ghostbusters" and realize that it is not a movie about chasing ghosts, but about relieving oneself of the burden of the past (past=social injustice) and accepting an entrepreneurial, self-serving future. And so on.
Understanding social consciousness and unconsciousness is very important in being able to speak effectively and to convince people that you do understand how the world works. Communication and working through our common conditioning is a form of action.
Joanna