The proposal freudiana considered the human beings as natural objects submitted the natural causes and laws. In this perspective it is that it faced the challenge of the joint between body and mind, supported in natural science and the theory of the passions, both prevalecentes at its time. It based its study in the estimated one of the law of the inertia, that differentiates activity of rest, what it demanded of beginning an approach of quantitative nature (natural science), receiving complementary a boarding qualitative (theory from passions), that it folloied its consideraes concerning the phenomenon of the conscience. Thus, it points with respect to the peculiarity of the pleasure notion considering that the human being is endowed with a nervous system whose architecture would be organized around the function to keep the variation of received stimulatons equal or next to zero. Initially, Freud, only considered the nervous system as a set of neurons, however, the diversity of excitement sources or stimulatons finished being the responsible one for the full constitution what it called in this workmanship of neurological device, as well as of its functions, as perception, memory and conscience. Freud does not only make reference to reference the external stimulatons. It affirms that the nervous system receives stimulatons from the proper corporal element, internally, of the order of the hunger, breath and sexuality, operating in a way that does not allow to esquiva or elimination for the consequence-motor action.
Therefore the nervous system starts to promote storage of part of this stimulaton, and thus to manage it in order to be used to provoke alterations that take care of to its demands; From then on, the performance of the beginning of the pleasure starts to be the elimination of the excess excitement, taking care of to the requirement to hinder that any external stimulaton damages the system while it conserves a small portion of it, keeping its constant level. Consideraes final Is concluded, therefore, in Freud, that the quantitative point of view or natural science is not disentailed of qualitative or the theory of the passions, that takes in account the constitution of the mental or psychic functions, of the motivations of our actions, of the reasons to prefer or to command a chain of ideas or action to another one. Without the qualitative factor our thoughts if would put into motion mismanaged without direction or objective. It is identified, in the particularitity of the notion of pleasure conceived for Freud, the possibility to think the displeasure, and same pain, as factors that they put as much body as the mind in movement, rank that stimulates the system to the fulfilment of its primary inclination since pain results of extreme a quantitative increase. Therefore, pleasure and displeasure always would be related to the occupation of the system with approach of the passions in the mental constitution. Being thus, its theory demonstrates the clear notion of that the pleasure would be related to the discharge of the excitement or the extreme amounts.