From this point of view, it is seen that poststructuralist thought has a lot in common with the post-empricisim and assumptions of Frankfurt School in critical theory. All of these approaches share similar ideas about the central role of language to the construction of social life, the historicity of knowledge (it means knowledge is related with power and is historically produced within socio-cultural structures) and rejection of the idea of universal (timeless and spaceless) knowledge (Campbell, 2013: 232). In fact, as stated by Robert Cox, one of the prominent names of Frankfurt School, “theory is always for someone and for some purpose”. For this reason they reject the possibility of value-free social analysis. In other words, theoretical knowledge is not independent from the values, thoughts and ideological beliefs of the theorist.