In this article, we seek to unpack and enrich the notion of the design concept. We do this through the use of Gilles Deleuze and Felix Guattari's 'concept' in its philosophical specificity to critique less-effective uses of the design concept. In particular, we investigate the idea that a concept is actually an aggregation of many concepts that can be seen to have a virtual consistency as a way to reframing more limited, typical, design concepts--used as justification, explanation, clarification or excuse. Our interest here is to explore how concepts can become much more useful throughout the process of design by drawing linkages between the concept and the workings of the creative process itself. In other words, we see the concept, parsed philosophically, as fusing with design thinking; and by taking advantage of this coupling each strengthens the other. Ultimately, we claim that a richer view of language and a more perfomative processes of making (diagramming) drive this coupling; and when it is working, the design concept becomes a much more useful instrument for designing.