The Six-Day War in 1967 ended an era characterized by cultural exuberance and political optimism, ushering the Arab world into a period rife with economic anxiety and political unrest. Formerly powerful Arab armies disbanded. Firm social conventions were called into question. Radical movements (right and left) were on the rise. Maverick writers, philosophers, poets, and cultural critics authored influential critiques that profoundly undermined the ideals holding Arab society together, including Islamic faith and nationalism. The sea changes triggered by the war, however, resist easy categorization and defy simple historical narration that would attribute them only to the diverging trends of iconoclasm on the Left and traditionalism on the Right. The question of what exactly was defeated in the 1967 war continues to harangue historians and remains as relevant as it was in those tumultuous times. Historians may never stop arguing about which historical currents reignited the new intellectual debates that came to the fore in the wake of the defeat. These debates increasingly focused on the Turāth (roughly defined as the Arab past, cultural heritage, and authenticity) that irrevocably changed the political vocabulary and intellectual frameworks in the contemporary Arab region. For the vanquished Arab nations, the 1967 war marked two fundamental developments: First, it asserted the growing power of culture on shaping people’s political orientation and social choices. Formerly it was economic disparity that seemed to hold Arab society back. After the defeat, however, it was dated cultural norms, values and mores that seemed to bedevil Arab society even more. Increasingly the military defeat in the Arab-Israeli war in 1967 was conceived as a cultural defeat, steering many Leftist intellectuals to engage in cultural debates that relegated economic and political factors to the margins. Second, the defeat made it clear that the so-called Arab Turāth was not withering away. The war resuscitated Arab intellectuals’ attention to their past, cementing new cultural orientations that increasingly focused on Arab authenticity. While the debate surrounding the Turāth dates back to the late nineteenth century, it acquired new meanings and cultural relevance in the post-1967 era, as intellectuals began to take Arab post-colonial conditions into account. The Turāth challenged certain basic precepts that had been part of Arab culture, especially the faith in Western philosophies, the inevitability of progress, the linearity and homogeneity of time, and the universality of secularism. The Turāth encouraged a search for a forgotten Arab culture and gave rise to words like authenticity (Asalah) and cultural onslaught, which grew increasingly common. The discourse on the Turāth transformed Arab political and intellectual conversations in a variety of ways. It produced major political realignment, creating a coalition of previously left-wing and moderate Islamists in big-cities. It also strengthened North-African scholars’ presence in the post-1967 Arab intellectual landscape, spawning scholars like Jabiri who outlined the Turāth as the defining problem with which Arab intellectuals had to cope. It fundamentally altered the authority of the intellectual tradition that originated in Beirut and Cairo. It transformed the economy of the intellectual debates by introducing new cultural references, such as self-critique, that had been unpopular before the war. Above all, it led Arab intellectuals to view the Turāth less as a reservoir of archaic norms, and more as the ultimate protector of Arabs’ human dignity under Arab regimes, which were prone to viewing modern constitutions and legal laws as instruments of power rather than justice. The debate over the Turāth not only brought a new breed of Arab voices into the intellectual landscape, but it also led to the creation of the first anti-Turāth movement in the Arab world. The Arab Rationalist Association, a constellation of Arab intellectuals who gathered around Syrian writer Jūrj Ṭarābīshī in Paris, formed in protest against the cultural obsession with “things authentic.” These intellectuals argued that the Turāth literature was a mere means of escapism, distracting Arabs from their real and pressing problems, reinforcing older values, and dampening political radicalism. For these cultural critics, the Turāth literature is not politically neutral, but rather a literature that fosters cultural sensibilities that antagonize difference and look suspiciously at Western philosophies. The Arab Rationalist Association questioned everything from false attempts to fashion modern forms of reliving the past, to moderate Islamic moral codes, through different forms of patriotism. Who were the members of the association? What are the cultural and social concerns that banded them together? Why did they reject the Turāth and to what ends? This dissertation illuminates why the Turāth gained more traction in post-colonial society and how it changed the Arab intellectual conversation.