William F. Buckley, Jr., perhaps best described the importance of this seminal work when he said, "James Burnham has written a book about Liberalism for which the world has been aching. It is worth more to the West than the year's gross national product, more than all the planes and bombs..."

Through studious research into past civilizations, Burnham diagnoses the twentieth century and finds it afflicted with destructive, even "suicidal" tendencies––all of which arise from the "Liberal syndrome" and its inherent applications.

The book explores several important questions, including why Liberalism clashes with Christianity and how Liberalism is a root cause of race riots and the rapid growth in crime. For James Burnham, who died in 1986, this book is certainly one of his greatest legacies.