Sense Data - The Nature of Sense Data

The Nature of Sense Data

The idea that our perceptions are based on sense data is supported by a number of arguments. The first is popularly known as the Argument From Illusion. From a subjective experience of perceiving something, it is theoretically impossible to distinguish perceiving something which exists independently of oneself from an hallucination or mirage. Thus, we do not have any direct access to the outside world that would allow us to reliably distinguish it from an illusion that caused identical experiences. Since (the argument claims) we must have direct access to some specific experiential entity in order to have the percepts that we do, and since this entity is not identical to the real object itself, there must be some sort of internal mental entity somehow correlated to the real world, about which we afterwards have perceptions, make judgments, etc. This entity is a sense-datum.