This dissertation argues that European Union membership conditionality operates as a modality of political-economic governance directed at securing the conditions of possibility for a harmoniously functioning political economy of Europe. I argue that conditionality can best be understood not as a series of requirements for EU membership, a set of incentives for rule adoption, or a vehicle for the transmission of European norms to candidate states, but as an ensemble of discursive and material practices – fragile, dispersed circuits of governmental activity directed at a particular strategic ambition. I argue that existing accounts of EU membership conditionality are informed by predominantly rationalist understandings of political economy which work to conceal various cultural, social, and subjective sources of disharmony in political-economic life. Thinking about the political economy of conditionality through rationalist lenses privileges the study of bargaining and negotiation and institutional reform and overlooks the ways that conditionality targets the transformation of problematic socio-cultural and subjective elements of political economy – among them particular habits of culture, patterns of sociality, and subjective qualities and capacities of the person deemed essential to securing order and abundance. Re-reading canonical works in classical and critical traditions of political economy by James Steuart, Adam Smith, and Karl Marx makes clear that political economy as a field of knowledge and practice has long been concerned with understanding the political, legislative-legal, institutional, socio-cultural, and subjective conditions of possibility for securing order and abundance and has long reflected on the potential and limits of governance to secure these conditions in a world of shifting circumstance. I argue that a political economy of EU membership conditionality concerned with disharmony should investigate the ways that particular socio-cultural and subjective features of political-economic life are problematized in the discourse of conditionality and subsequently targeted for transformation through the work of instruments and agents of conditionality operating in a variety of institutional contexts. On this basis, I analyze conditionality as practice – tracing the emergence of instruments of conditionality currently at work in the Republic of Macedonia through official documents produced by the EU and the Republic of Macedonia from 2001-2011. I then examine the ambitions and limits of the Operational Programme Human Resources Development 2007-2013 (OP-HRD) – a program tasked with translating the aims of conditionality on paper into concrete activities for implementation in the fields of employment, education and training, and social inclusion. I outline some limits to the program derived from personal interviews with officials of the EU and the Republic of Macedonia who work to implement the OP-HRD "on the ground." In reflecting on these limitations, I return to the political economy of disharmony, concluding that constraints on the operation of conditionality in practice are not merely the product of technical and political impediments but are also derived from inherent limits to the old dream of political-economic harmony to which the ambitions of conditionality are ultimately directed.