Studying the (on average) higher fertility of religious populations from an evolutionary perspective for some years, I have been somewhat sceptical about applying such observations in the contemporary field of political analysis. But Eric Kaufmann did the job. Making clear his own, rather secular position, he is nevertheless avoiding biasses or polemics, but is informing the reader. He manages to do this by patiently combining available demographic data, historical descriptions and case studies on a wide range of populations as i.e. Haredim Jews in Israel, Mormons in the US, strong Calvinists in the Netherlands, Salafist movements in the Muslim world and many more. Although he is discussing projections and problems, Kaufmann doesn't fall into the trap of mindless alarmism, carefully weighing further options for secular und moderate religious movements, too. Although my interest started from the purely empirical and evolutionary side, I began to like the book for its political and philosophic clout in presenting tough questions and tentatively probing for new answers. For almost any reader, this will be a captivating and thought-provoking read and for scientists from different fields a chance to discuss, test and revise or expand sound observations and hypotheses.