This article examines a distinctive conception of knowledge developed in the later Middle Ages, focusing on Thomas Aquinas (d. 1274) and his followers Lambertus de Monte (d. 1499) and Magnus Hundt (d. 1519). It reconstructs an understanding of knowledge that was already unusual in it original context and remains unconventional today, yet becomes plausible once the problem it addresses is properly understood. Central to this approach is a close connection between concept and thing: both are understood as expressions of the same reality, albeit in different modes. This ontological proximity has far-reaching consequences for epistemology. Knowledge is not conceived as a mere collection of facts but as a way in which reality articulates itself through concepts, which themselves are part of that reality. A discussion of the theses of the Swiss mathematician Ferdinand Gonseth (1890–1975) serves to clarify the philosophical problem at stake in the medieval context.