  Representationalism has been quite popular in recent years and had many defenders, but it remains highly controversial and intuitions clash about key cases and thought experiments (Block 1996). In particular the possibility of inverted qualia provides a crucial test case. To anti-representationalists, the mere logical possibility of inverted qualia shows that conscious states can differ in a significant mental respect while coinciding representationally. Representationalists in reply deny either the possibility of such inversion or its alleged import (Dretske 1995, Tye 2000).