This thesis recovers Spain’s engagement with the Utrecht Enlightenment. Early eighteenth-century Spanish history saw speculation as the means to make sense of a changing world. Political writings transformed social speculation into political debate. Fears about usury failed to influence debates about the merits of enemy investments in imperial joint-stock companies. Speculation fomented scrutiny and deliberation. Political speculation about an alternative set of alliances led Ferdinand VI to venture to secure peace in Europe. The anger that characterised Philip V’s government gave way to bargaining and the currency of war was, for a short period, devalued. Some of the returns on these Spanish investments – such as Andrés Marcos Burriel y López’s quiet study of the intellectual origins of Spanish sovereignty – emerged later in the eighteenth century, and their origins went unacknowledged. Keen observers, such as the Marquis of Pombal, benefited from the Spanish investment in geopolitical speculation, and responded by designing their own system of European alliances. This, then, is a study of how, upon watching a global system of commercial relations and extractive practices slowly dissolve around them, Spanish thinkers imagined visions of progress that devised alternative models of social, political, and transnational cooperation; sources of hope in the possibility that the investment in a shared future would reaffirm trust in politics in a globalised world.