Athens Journal of Law April 2017 99 Between Creativity and Arbitrariness: The Search for Legitimacy and Rationality in Constitutional Reasoning By Rafael de Oliveira Costa  This article focuses on the necessary interaction between law and ethics in interpretation of norms, arguing that the attitude of the judge, legislative impact assessment and the procedure to reach a decision, more than its content, should be taken into consideration to ensure (formal and material) legitimacy of decisions. The proposal to reconsider the problem of rationality and legitimacy of judicial decisions from the perspective of philosophical hermeneutics is very useful for a deeper understanding of the creative power of the judiciary, especially because it is impossible to guarantee the correct answer, which does not allow the interpreter to give any meaning to norms. It inaugurates a new approach, which prioritises questioning about the very phenomenon of hermeneutics (no longer limited to the study of suitable methods to discover the true meaning of the norm). Thus, this study seeks to understand the impact of revelations brought by philosophical hermeneutics to control creativity in Law, an issue chosen for debate by representing one of the great contemporary hermeneutical challenges. Considering the juspolitical function of supreme courts and the lessons of philosophical hermeneutics, I determine the role of hermeneutics in controlling judges’ creativity and assuring that decisions are ethically grounded, arguably legitimate and rationally appropriate with the principle of separation of powers. Furthermore, I associate, in a democratic state, enforcement of fundamental rights with the rule that prohibits courts from acting as lawmakers. Keywords: Constitutional Reasoning; Hermeneutics; Ontological-linguistic paradigm. Introduction The debates about decisionism and existence of the correct answer are two of the most important in the general theory of law and have received several contributions in recent years. 1 Intending to overcome legal positivism, many scholars have urged the use of interpretation and the linguistic-ontological paradigm to solve the issue. In this article, focusing on the necessary interaction between law and ethics in interpreting norms, I argue that the attitude of the judge, the legislative impact assessment and the procedure to reach a decision, more than its content, should be taken into consideration to ensure (formal and material) legitimacy to decisions. The proposal to reconsider the problem of rationality and legitimacy of judicial decisions from the perspective of philosophical  Professor, Universidade Anhanguera and Prosecutor, Ministério Público do Estado de São Paulo, Brazil. 1 See Dworkin (1966) and Alexy (1998).