immanent criticism—that is, by exposing  how  the  existing  social  reality  fails  to  live  up  to  the  normative   claims   contained   within   it. 

By  the  mid-1960s,  however,  Habermas  seems  to  have  had  growing doubts about this version of a “philosophy of history with practical  intent.”  It  is  not  entirely  clear  what  motivated  him  to  change  course  at  this  time,  though  it  may  have  had  to  do  with  doubts  that  the  specific  form  of  immanent  criticism  he  proposed  would be sufficient. He suggests that “bourgeois consciousness has become cynical” in the sense that even exposing bourgeois society to its failure to live up to its own ideals might not be sufficient to persuade it of the need for change (CES, 97).

It referred to any “space” where private citizens gathered to debate what was in their common good, and its more specifically political function was to serve as a check on the exercise of political power.