The sense of touch is of particular importance for virtual environments as it is supposed to offer tangibility to virtual objects. However, to do so, we have to deal with an epistemological difficulty: on one hand, it seems that we need an advanced knowledge on human perception to improve these devices, while, on the other hand, the acquisition of this knowledge supposes already an advanced development of interfaces as measuring devices. On which epistemological basis to study the emergence /the perception of objects in VR? Are the interfaces the goal of the studies on human perception or are they a mean for such studies?