This article provides a critical review of Patrick Deneen's book, Why Liberalism Failed?, reconstructing its central argument: that the current crises of liberalism stem not from a deviation from its founding principles, but from the historical and internal fulfillment of this intellectual tradition. Deneen views liberalism not merely as a political regime or a set of policies, but as a comprehensive philosophy regarding humanity, freedom, politics, economics, culture, and education. According to him, modern liberalism's emphasis on radical individualism, self-foundation, and absolute liberation from traditional and social constraints has led to the weakening of mediating institutions, the erosion of shared culture, the expansion of social inequality, the dominance of technology, and a crisis of democratic legitimacy. In addition to systematically outlining the book's main themes—ranging from the concept of "counter-culture" and the critique of technocracy and liberal education to the analysis of neoliberalism and liberal democracy—this article critically evaluates its theoretical and methodological shortcomings, including conceptual ambiguity in the definition of liberalism and the predominance of interpretative readings over empirical and comparative evidence. In the concluding section, the relevance of this critique to Iranian society is examined, demonstrating that although liberalism in its classical sense has not been established in Iran, Deneen's internal critique can serve as an important analytical framework for understanding contemporary crises in governance, technocracy, education, and political economy in Iran.