[Pleasure, pain and affectivity in the nervous system]

Affectivity plays an essential role in human life. It gives life its quality, and is responsible for what human beings have always considered to be main endeavor happiness. Still, looking for its description or organisation, in physiology or neurology, treatises is fruitless; there only one of its components is described pain, with no mention of pleasure. We wish to show, here, first, that pain and pleasure, depend of a same function, of which they are, of sorts, both extremities, and which in nothing but the most primitive function of the nervous system, and secondly, that this function in one of the components of an "affectivity center", which has its organisation in the limbic system. This center, integrating all the informations that arrives to the nervous system, triggers to each of them neuro-vegetative and neuro-hormonal informations that are "felt" by the organism, and thus transforms the information in a subjective feeling.