Book after book, Pierre-André Taguieff continues to work on deciphering the concepts of political thought, never taking the easy way and radically challenging the positions willingly from the analysis militant judgment. For this exercise, it does not choose the least complex concepts, having instead a preference for those with partisan connotations just draw a very narrow ridge line: racism, populism, nationalism and extreme Rightist, etc. In this test, it is especially populism and nationalism in question, indicating the author in introducing what will be his position to grasp these two concepts: "In this essay, I take distance from this vision overall negative and moralizing of 'populism' and 'nationalism', which is under a polemical spirit nurtured militant convictions fixed, codified and ritualized indignation and good feelings. But I forbid summarily reverse the negative value judgments on these two ideological and political phenomena (...). I try to avoid as much celebration as the naive blind criminalization "(p. 25). In the same vein, he attacks the lazy attempts to transpose analysis sections valid for the past to present realities, critical in this respect the "chorus of a rebirth of fascism." "Faced with this shocks us, we suffer too many reminiscences to hope to understand" (p. 194). While it is interesting, the book does not seem, however, be part of the best Taguieff. I also perceived more as a series of articles on both subjects - populism and nationalism - as the result of a real increase in reasoning. In this regard, the new national populism, published in 2012, had seemed more convincing. Another point bothered me: apparently careless use of the term "xenophobia" - until the subtitle of the book - as if, paradoxically, information that had given the author to address concepts problems did not apply to this category, yet oh so exclusionary, since its primary meaning of "hatred of foreigners". Perhaps the subject of a future book?