 The Knowledge Argument has traditionally been understood as an argument against physicalism or perhaps against reductive versions of physicalism. But an influential alternative approach sees the argument as working not against physicalism per se, but against a different position which can be termed  objectivism.[7]  Objectivism is the view that an objective description of what exists can be complete; that there are no aspects of reality which can only be understood by having experiences of a specific type. This notion is closely related to Nagel’s characterization of the physical nature of organisms as “a domain of objective facts par excellence – the kind that can be observed and understood from many points of view and by individuals with differing perceptual systems” (1974, 442). On this view, the point of Jackson’s thought experiment is to bring out that Mary learns something which can only be known by having an experience of a certain kind (e.g., a perceptual experience). If this is correct, then this shows that no objective description of what exist can be complete. As Howell formulates it, the argument understood in this way runs as follows: