The paper starts with a discussion of the assumption that positions of the outer world are coded by the anatomical locations of firing neurons within retinotopic maps ("coding position by position"). This "code position theory" explains space perception by some kind of structural isomorphism since it implies that the perceptual space is based on a spatial structure within the brain. The axiom of structural isomorphism is rejected. Subsequently, a sensorimotor account of space perception is outlined according to which the spatial structure of the outer world is coded by the temporal structure of cortical processing. The basis is that action changes the perceiver's relationship to the outer world and, therefore, changes the representation of the outer world coded by the sensory responses of the brain. According to this view the code for position is not a spatial but a temporal structure resulting from action ("coding position by action"). The sensorimotor account offers a possible solution to the binding problem. The paper ends with some remarks on the possible origin and function of retinotopic representations.