The nervous system only interacts with relations. However, since the functioning of the nervous system is anatomy bound, these interactions are necessarily mediated by physical interactions. For animals to discriminate objects by vision, the receptors in the eyes must absorb light quanta to be activated, yet the objects that the animal sees are dtermined by the realtions of the receptor-induced activity within the functional and anatomical organization of the retina. Moreover, since the domain of interactions of the organism is defined by its structure, and this structure implies the prediction of the niche, the relations with which the nervous system interacts are defined by this prediction and arise in the domain of interactions of the organism. The (anatomical and functional) organization of the living system defines a point of view, a bias or a posture from which the interactions take place, and that determines the possible relations accesible to the nervous system. The anatomy of the retina and the properties of the various cell types define which relations, holding between the active receptors when a given visual object is viewed, will be accessible to the nervous system. (NC 12)