Those who defend animals claim equal rights between human and nonhuman, and thus call into question the perspective on justice and politics as forms of representation exclusively of humans. This problematic fits into the current debates about the ontological turn in the social sciences and at the same time allows to deal with the action of defenders as a form of environmental controversy insofar as it discusses another understanding about humanity and animality. In dialogue with Anthropological and Sociological theories, this work aims to understand the relationship between animal law and justice and at the same time the ontological transformations brought into play from this form of claim. For the accomplishment of this work was used bibliographical research, investigation on the publications made by the defenders and critical situations, involving animals, through vehicles of communication. It was possible to observe that, although modernity is characterized by separate poles of nature and culture, defenders think of this division from blurred borders, since they include humans and animals in the same model of politics and representation of justice.