Slavoj Zizek: What is a Master-Signifier & The Antinomies of Tolerant Reason

Zizek begins his theoretical project in Sublime Object by taking up Laclau and Mouffe's notion of 'radical democracy'. As he admits in his Acknowledgements there, it is their book Hegemony and Socialist Strategy that first oriented him in the use of the 'Lacanian conceptual apparatus as a tool in the analysis of ideology' (SO, xvi). What is the essential argument of Hegemony and Socialist Strategy?
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To many a Western historian of religion, Islam is a problem – how could it have emerged after Christianity, the religion to end all religions? Its very geographic place belies the cliché on Orientalism: much more than belonging to the Orient, the location of Islam makes it a fatal obstacle to the true union of the East and the West – the point made exemplarily by Claude Levi-Strauss:
  [Moins]