The Theory of Communicative Action, Volume 1

This is by far the hardest book I've ever finished. Habermas is supremely knowledgeable and is not the most clear of writers, but this book and the second volume are a tour de force. I particularly liked how Habermas relies on an action-based framework to base his whole philosophic construct on. Leveraging, Rawls and other analytical philosophers to update his Marxian-influenced theories was refreshing (not to mention Luhmann's system theory). Overall, I certainly felt very convinced at the end but would struggle to clearly articulate what Habermas theory is