Design has usually been linked to art and applied in scenarios related to everyday life. Even when design has, on occasion, made its way into the world of academia, it has always been closely linked to art and scenarios related everyday life. At last, however, the idea of design has reached the field of epistemology: an area within the very heart of philosophy that has always focused, in theory, on the foundations of knowledge. Consequently, design is being studied from different (...) approaches interested in the foundation of knowledge, theoretical and practical. This is one of the reasons why abduction and pragmatism have been considered relevant from a design perspective. This paper first shows the main features of abduction and pragmatism, describes their evolution and considers their mutual implications. Second, the epistemology of design is analysed considering its most relevant characteristics. Third, the connection between abduction and, on the one hand, pragmatism and, on the other, design epistemology is addressed. Finally, the role of abductive inference in grounding a real epistemology for design theory from the naturalised cognitive perspective of abduction is outlined. The central proposition is that this approach is essential as a methodological innovation, as it allows us to analyse both the inquiry process and the design process as interdependent when dealing with practical problems of a social and cultural nature. This approach allows us to analyse how human actions determine changes in the theoretical framework from which we make our inquiry. In short, the world is an open-ended project that humans design through our daily inquiry. (shrink)