 Further, it is “given” that ego and non-ego are mind and matter and that these are co-equal. Hamilton’s preferred position, which he called “Natural Realism” or “Natural Dualism”, affirmed the datum of consciousness and held that some portion of the external world is given to the subject in immediate perception. He argued that, in vision, the physical retinal image is the immediately given material entity (1861, 2: 130, 179–184). Accordingly, we have intuitive knowledge of a two-dimensional image, which we are able to understand as a projection of the three-dimensional physical world. This position would allow Hamilton to reject Hume’s Argument from Perceptual Variation, because the “real object” of perception, the retinal image, does vary as we approach or recede from the real table. On this view, we don’t immediately perceive the real table, but we infer it from a real item of the external world that we do perceive immediately: the retinal image.