Do you know which theory you want to belong to. There is Charles Darwin, Karl Marx, Claude Levi-Strass, and Serge Malinoswki respectively evolutionist, marxist, structuralist and functionalist theorists. They have been used in sociology, ethnology and economy for example. Charles promoted the free world whereas Karl Marx used the concept of contradiction. The students should know now that there is no need to think that researchers torture themselves in their research because they try to prove a theory. A theory is the way the work for example can be done and in the word theory there is the prefixe “theo” which means God.