Designed objects are here, there, and everywhere, but do designers always have full consciousness of their knowledge: the knowledge that planned, designed, produced these objects, and changed life conditions? Moreover, even though they did have this consciousness, did they always have the will to make this knowledge or expertise public that they share on a day-to-day basis with their coworkers? And finally, how did this design knowledge become reflective? What claims are made concerning this reflexivity, which seems to be gradually taking place inside the design discipline?