This article aims to present the topic of judicial activism under the paradigm of so-called ‘state of fundamental rights’. Rather than devote itself to reflect on concepts, ratings and reviews related to judicial activism, the purpose of this paper is to shift the gaze of activism played only by judges, but also focus on activism starring other actors of power, what will be called constitutional activism. It is a dogmatic research, with analytical nature, which proposes three approaches to the phenomenon studied: one ideological, other theoretical and methodological still last, which assume that the interactions, cooperative or conflictual, between the functions of state power are evaluated and controlled for each function of power reciprocally. It is proposed, as the main parameter for this assessment and control, the fundamental rights’ theory, with its inseparable link to proportionality, what means substantive due process as a result of a substantive vision of the Constitution. The triple classification of constitutional activism presented here has the intention to leave the commonplace that the issue has been handled, trying to convert activist practices in reason, posture and constitutional attitude, which are unpublished concepts that may hereafter be experienced by those who, being real interlocutors of state power, quasi-state or non-state, present themselves as protagonists of the practical realization of dynamic constitutional standards, especially of the fundamental rights.