[Science, public health and nursing: highlighting the gender and generation categories in the episteme of praxis].

This essay aims to show the relevance of sociological categories gender and generation that underlie the phenomenon of nursing in public health, the episteme of praxis. We understand praxis as the foundation of the historical and dialectic materialism, demonstrating its importance in the process of construction of knowledge in public health nursing. The sociological categories of gender and generation were chosen in this paper because it has the privilege to better illuminate certain phenomena that have been the subject of scientific concern, such as violence against women, children and the elderly, in all its vulnerabilities. The dialectical method was adopted, with an emphasis on the secondary laws of "essence and phenomena" and "reality and possibility". Finally, given that the choice of the approach to the object, as well as the instruments for intervention towards a purpose in the process of scientific knowledge is the choice of the knowing subject, the ethics was related to praxis.