Then, expand that idea. Write about the ways you see some of these theories affecting how you or how other people actually make decisions in life. This is tricky. People don't walk around saying things like, because Marxist theory affects how I think about the world, I'm not going to buy a new car but instead buy a used one. But, in fact, a belief that we don't want or need a lot of new stuff all the time is shaped by a belief system and that belief system is based on one theory rather than another--or a combination of theories.
Once you've posted, read and respond to more than one your colleagues.