Estudoprofundo of we ourselves in will give the mathematical evidence to them for which ficaremoscertos, if in our thought it has some thing that has different principle denossas laws or if they are only manifestations and combinations of these same laws, enos it will teach the true job of the directions and the reflection. The knowledge that we have of the directions in them offers to asseguintes truths: That certain bodies only have a likeable, proper force to move this or that direction. That the nerves with the irritability property are the essential part of the directions. That the same likeable bodies do not walk in the directions seno until where if they find the nerves and that nothing more they make that to shock them and to communicate its impression to them. It is known therefore, the truth of the two last ones results eque, being born the man in the great theater of the nature, depending on it, needed agencies that served to it of instrument to form the league comaquelas parts of the nature on that it depended, and that it they were guides segurospara, for them, to look for what it agreed to it and to run away from what it he was harmful. Here it is here the usefulness of the directions: for them we do not know the nature in itself, external anatureza; but, for our feelings caused for them, we feel aimpresso that the external objects make on us, that it is how much is enough to parapodermos to provide our conservation and good to be. It can be observed that ossentidos and the reflection does not give in them, in them do not present objects, but somenteso occasion of that the soul develops, puts in exercise its facultieses. They are, therefore, the sensations the first material of the human knowledge, considered in relation to the objects cause that them, and carried aosmesmos for a habit contracted since the first moments from our existnciapor a done instinct of the necessity to mark objects that they must serconhecidos in them for the influence that exercises on us.