Martin Jay is one of the most respected intellectual historians now working, and any book by him is an important event. His subject here could hardly be bigger: the idea of reason in Western thought over two millennia."" - Michael Rosen, Harvard University""A magisterial rethinking of the fate of reason, particularly in German philosophy from Kant to Habermas."" - Anson Rabinbach, Princeton University""The overriding strength of Jay's book is the breadth and depth of the intellectual history of reason it offers, a history that illuminates Critical Theory's concern to criticize our deeply imperfect societies, and the damaged lives they produce."" - Notre Dame Philosophical Reviews""A magisterial rethinking of the fate of reason, particularly in German philosophy from Kant to Habermas."" - Anson Rabinbach,Princeton University