This thesis is geared towards assessing the role(s) ('positive', 'negative', etc.) of certain cultural 'codes' in the constitution of oppositional social movements - including (but not limited to) codes associated with “counter culture”. In orienting itself as such, it takes as its starting point certain social movement discourses, asking whether they are not bound up in dissonances arising from the contestation of such cultural codes. More precisely, it observes that across multiple regional nodes of the 'movement of movements' in the global North - and particularly in those nodes continuous with anarchist, non-Leninist Marxist, and direct action-oriented political traditions - intense dialogues have occurred since the late 1990s as to questions of movement strategy and orientation. Although they take apparently disparate forms - around questions of “actionism” and activist ghettoisation; of “lifestylism”; of “summit-hopping”, etc. - this paper views these dialogues as fundamentally interlinked, and seeks to explore this linkage in terms of contradictions deeply rooted in the long-term evolution of the movements - and in terms of movement actors' struggles with those contradictions. Ultimately, the thesis casts many of the contentious issues at the centre of intramovement dialogues as arising from the contradictions of the movements' 'counter cultural' heritage. Having considered the problems associated with this heritage, and the reaction against it on the part of movement actors, the thesis goes on to ask whether counter culture, understood as one element of a broad libertarian drift within popular culture, could not also be seen as an important toolbox for oppositional movements to draw upon: as a matrix not just for what is still meaningful in flawed and taken-for-granted notions of 'class struggle', but also (drawing on the work of certain anarchist and autonomist writers) for the actualisation of ubiquitous human potentialities toward freedom and “selfvalorisation”. As a pilot exercise in testing these questions out empirically, the thesis analyses data drawn from interviews with young newcomers to oppositional social movements in Ireland, asking how their paths to participation may have been influenced by antagonistic cultural codes.