In the submitted thesis the author focuses on the rising popularity of extremist political parties in the Czech Republic. The popularity growth of extremist political parties in the Czech Republic is proven by election results in recent years. Right-wing extremists{\crq} ``combat power{\crqq} growth is closely connected with the increasing number of their followers. Regional elections in 2008, in which the Labour Party achieved almost 29 thousand votes, which represents eight times more than the party had achieved in the previous elections in 2004, can be a proof of that. What is more, this party achieved 1.07% votes in the European Parliament elections and it surpassed the limit which is necessary for the state subsidy requisition. In the Theoretical Part the author deals with definitions of basic terms ``extreme{\crqq} and ``radical{\crqq}. Then he deals with the theoretical division of the political scene, from both the current point of view and the historical point of view, into the rights and the lefts. Then he attends to some terms which are closely associated with extremism, such as: nationalism, anti-Semitism and racism. In the Conclusion of the Theoretical Part the author focuses on the far rights and the far lefts. He pays attention to both the current representatives and to their predecessors of those extreme lines. In the Practical Part the author sets his targets and defines hypotheses and he also attends to the used research procedure there. The research was made via questionnaire investigations. Questions were focused on people{\crq}s opinions which are related to inadaptable citizens and extremism. There were also some questions which were focused on activities of those parties in the above mentioned fields, regarding the inadaptable citizens and extremism, which have their members in the Parliament of the Czech Republic. In the Practical part of the thesis the author also evaluates the observed results in light of respondents{\crq} achieved level of education. In the Discussion of the thesis the author compares the observed data with the knowledge of experts. He also focuses on divergent opinions of asked respondents, in connection with their achieved level of education. The thesis and the observed results could be used by general public interested in extremism in the Czech Republic. Besides, the thesis and the observed results could be used as a source of information to improve general knowledge about the scene of extremism and about the problems pertaining to the scene in the Czech Republic.

Du 11 septembre aux extraterrestres, des camps de concentration américains à l'assassinat de Kennedy, cette thèse a pour objectif d'éclairer sous un angle sociopolitique les fondements, les mécanismes et les enjeux de la pensée conspirationniste aux États-Unis depuis la révolution jusqu'à nos jours. S'il ne s'agit pas de dresser un catalogue exhaustif de toutes les théories du complot en vogue, le but demeure de démontrer que le conspirationnisme est un véritable fait social aux États-Unis, un élément de culture politique et populaire. Cette thèse se propose alors d'étudier les rouages et les origines du conspirationnisme sous trois aspects différents et complémentaires qui forment un triangle. D'abord, sous l'angle factuel, c'est-à-dire en étudiant les thèses du complot relatives à un événement extraordinaire (9/11, assassinat de JFK, etc.). Ensuite, sous l'angle des acteurs du conspirationnisme : les leaders conspirationnistes (LaRouche, Icke, etc.), les citoyens enquêteurs et les boucs-émissaires (communistes, juifs, illuminatis, etc.). Enfin, sous l'angle culturel en mettant en perspective le conspirationnisme avec la culture américaine : l'anti-étatisme, la présence de mafias ou encore le cinéma de masse. / From 9/11 to UFOs, from American concentration camps to the Kennedy's assassination, this dissertation aims to enlighten, through a sociopolitical analysis, the grounds, the mechanics and the goals of the conspiratorial thought in the United States since the Revolution. Even Though it is no question to draw an exhaustive catalog of each and every conspiracy theory, I would stress that conspiracism is part of the American political and popular culture. Then, this dissertation studies the origins and the developments of conspiracism through three complementary focuses. First, a factual approach which dwells on specific conspiracy theories such as the 9/11 attacks or the assassination of Kennedy. Secondly, I will come on the actors of conspiracism : the conspiracist leaders (LaRouche, Icke) the citizens sleuths and the scapegoats (Communists, Jews, Illuminatis). Finally, under a cultural angle, I will outlook conspiracism and the American culture of anti-statism, the presence of mafias or the role of mass-medias.