The necessity created the agency: larynx little developed of the monkey was transforming, slow more firmente, mediantes modulations that produced in turn modulation more perfect, while the agencies of the mouth little by little learned to pronounce a sound to articulate the other after (ENGELS, 1876, P. 18). This extracted part of the text of Engels illustrates as well as with acquisition of the erect position and from the work other necessities appear, in the cited example say, it and with it they had come new evolutions, new necessities The work starts exactly with the elaboration, and for in practical of the instruments for transformation of the nature. It starts when we think about something, (subjectively), in the necessity of this something, and from there elaborate we it mentally, (previous-ideao), we think about the materials, in as it would be and in its functioning, he stops later placing it in practical or (objetivao). The work, the manuscript forms of substances, and its evolutions, go being transferred of generation to generation and more go being each perfected time. The work is necessarily the relation of the man with the nature, to transform it as its necessities. The animals are not fit in the category to transform the nature, in view of that they do not transform, do not think to act, only make what already it came being made for passed generations, what comes definitive in its genetic codes. That is, it puts in practises its vital activity, as survival, reproduction of the species According to Lukcs ' ' So that the work can be born, while dynamic-estruturante base of a new type of being, is indispensable one determined degree of development of the reproduction process orgnica.' ' man if differs from the animals for the conscience, capacity to define ways and to search solutions that make possible the reach of its objective, having the choice freedom.