In this chapter, Lyotard’s notion serves as an intellectual framing of how a specific reasoning (cf. Hacking, Studies in History and Philosophy of Science 23(1):1-20, 1992a) develops within the educational sciences that eventually leads to the construction of international large-scale assessments (ILSA) and how this reasoning gains legitimacy within both science and policy embedded in a larger societal frame of meritocracy. To this end, this chapter historicizes some of the historical trajectories facilitating the construction of the first truly comparative assessment based on a positivistic inspired aggregation of numbered data. This first IEA (the International Association for the Evaluation of Educational Achievement) study was eventually followed by a multitude of different ILSA. In this, special attention is given to five important trajectories necessary for ILSA to occupy their present role in today’s meritocratic system: (1) how the scientific revolution changed and framed epistemological beliefs, (2) how the role of experts and expertism (Popkewitz, Paradigm and ideology in educational research, London and New York, 1984) changed, (3) how the introduction of statistics facilitated new ways of demonstrating the world and ‘reality’, (4) how the long-forgotten work by the French empiricist Marc-Antoine Jullien was used for a longer and legitimate history of a special branch of comparative education and (5) how the governing of matter and minds has changed over time. All these trajectories are important for an understanding of how ILSA became intelligible in a meritocratic context.