Perception of Absence
We are able to see what is not there, such as when a car has been stolen and is not where the owner expected it to be. There is some kind of phenomenological feel to such discoveries but it is uncertain and elusive. There is a distinction between seeing the absence of something and merely inferring its absence from what is seen. Two theories of how it is possible to see what is not there are considered: perceptual theories, which claim absences can be experienced, and cognitive theories that appeal to an inference. Both have problems. Perceptual theories struggle to say how something that is not there can be an object of perception while cognitive theories cannot say how the required inference is drawn. As an alternative, an evolved mechanism is invoked that allows a non-deductive inference to an absence that is then presented in the mind as experiential.