Philosophers usually emphasize the importance of logic, clarity and reason. Therefore when they address political issues they will usually inject a dose of rationality in these discussions, right? Wrong. This book gives a lot of examples showing the unexpected level of political irrationality among leading contemporary philosophers. The body of the book presents a detailed analysis of extreme leftist views of a number of famous philosophers and their occasional descent into apology for—and occasionally even active participation in—totalitarian politics. Most of these episodes are either virtually unknown (even inside the philosophical community) or have received very little attention. The author tries to explain how it was possible that so many luminaries of twentieth-century philosophy, who invoked reason and exhibited rigor and careful thinking in their professional work, succumbed to irrationality and ended up supporting some of the most murderous political regimes and ideologies. The huge leftist bias in contemporary philosophy and its persistence over the years is certainly a factor but it is far from being the whole story. Interestingly, the indisputably high intelligence of these philosophers did not actually protect them from descending into political insanity. It is argued that, on the contrary, both their brilliance and the high esteem they enjoyed in the profession only made them more self-confident and less cautious, thereby eventually making them blind to their betrayal of reason and the monstrosity of the causes they defended.