Before I tackle this point, I think I should say a few words on the notion of “epistemic object.” The general thrust of my whole argument is about the power of material objects—in contrast to ideas or concepts—as driving forces in the process of knowledge acquisition. Consequently, I am somewhat surprised to find my work categorized, in David’s critique, under the label of “linguistic idealism.” My goal was to provide an objectcentered, materially founded account of knowledge production. According to my position, scientific or epistemic objects are clearly material things. They function as scientific or epistemic objects by virtue of their opacity, their surplus, their material transcendence, if you like, which is what arouses interest in them and keeps them alive as targets of research. The fact that referentiality is not what characterizes their essence does not, by any means, as I see it, catapult them into the realm of the ideal. They