Michel Foucault builds a genealogy of critical activity of western philosophies from the word parrhesia or openness, the parresiastes being a critic, who knows the risk of telling the true but he has the courage to speak to said it to help other people to improve himself. It makes political praxis a moral issue, problematizes the limit of truth in democracy, making the truth a problem of the relationship with others and with itself, but also, a whole problematization of the praxis, of the political class, as an ethical problem or double moral.The parrhesia is connected with freedom and or duty, the true, the knowledge, thesubjectivity and the social and political praxis. It distinguishes two kinds of parrhesia as a result of praxis in the democratic or public institution and that practiced by citizens on a private level. He gives particular importance to the care of himself, is an insurgent. Foucault sees in parrhesia a mechanism for the analysis of political praxis in democratic society, emphasize the importance of morality as a starting point for freedom of expression and justice.