Eliminative materialism (also called eliminativism) is a materialist position in the philosophy of mind. Its primary claim is that people's common-sense understanding of the mind (or folk psychology) is false and that certain classes of s that most people believe in do not exist. Some eliminativists argue that no coherent neural basis will be found for many everyday psychological concepts such as belief or desire, since they are poorly defined. Rather, they argue that psychological concepts of behaviour and experience should be judged by how well they reduce to the biological level. Other versions entail the non-existence of conscious mental states such as pain and visual perceptions.