In this provocative book Popper, in my opinion one of this century's great philosophers, attacks the idea that history can be undersood by means of abstract laws. This approach to history Popper calls historicist. For example, Marx argued that due to the innate instability of capitalism, the latter would inevitably colapse, giving way to communism - this was supposed as a scientific fact. This type of prophetic argument presupposes that one can first discern the underlying mechanisms of historical change, and then (because knowing how something works is distinct from being able to predict outcomes) predict how history is going to develop. In the book, Popper attacks this type of prophetic argument with a force and effectiveness that blows historicism appart. Popper's chapters clearly show that vast unexplained clefts exists between many of Marx's postulations. Popper also indicates that Marx had no understanding of how science works: science is not about fulfilling predictions and does not preceed on the basis of verification. At the end of the end of the book, Popper widens his scope and identifies, in my opinion correctly, CERTAINTY as the great enemy of the open society. This book is important reading. It tackles some of the most pressing arguments of the 20th century and therefore should be read. One crown is lost because Popper seems to place to much faith in scientific method as a model of how society could be run.