Habermas' Theory of "Public Sphere" and Its Characteristics

Jurgen Habermas' consists three key elements,i.e.,the public,public opinion,and public media and the public place.There are four types of public spheres: representative public sphere,bourgeois public sphere(liberal mode of public sphere),plebeian public sphere,and the mass-democratic social-welfare sphere.Public sphere was not only the tangible history throughout the development of Europe in the 17th and 18th centuries,but also an ideal mode.It is a tool that Habermas used in his social criticism.