 Experiential theories seek to explain depiction in terms of the kind of experience a picture causes in a spectator, rather than the kind of representational system to which a picture allegedly belongs, or the spectator-independent resemblance or isomorphism between a picture and the objects it depicts, or the subpersonal cognitive mechanisms a picture may be thought to engage. It remains an open question whether theories of this kind can avoid the charge of circularity, in other words, whether it is possible to define the experience of seeing what a picture represents without employing the concept of depiction. But even among philosophers who believe that this is possible, the exact nature of the experience has been a matter of debate.