Legislation is a complex process that is organized by ijtihad as a special model of self-reflection and rationality, and "a specialized and proprietary approach to the role play of reason" is one of its constituents. The methodology of ijtihad requires that the tripartite processes of socialization of the actors, the formation of the physical structures, and the operationalization of legislation be formulated in accordance with the truth of ijtihad and its constituents, and be reproduced in accordance with the time, place and social reality. Otherwise, the outcome of the legislative process will not be coherent and effective. Using a descriptive-analytical approach, the case study of negation in the Islamic Penal Code, adopted in 1392, seeks to answer the question of whether the role played by reason in the legislation with a specialized and proprietary approach would lead to a fundamental distinction in validating the legal material and streamlining the law. This question is rooted in the current situation of legislation, which, concurrent with widespread developments, suffers from frequent and multiple production and reproduction of negations which has led to the degradation of the efficiency of reason and the validity of ijtihad in managing social reality. If the validation is done according to a specialized and proprietary approach based on the requirement of the lack of negation, then the apparent and recurrent negations are not produced and reproduced and the validity of the role play of reason and the effectiveness of ijtihad in legislation is revived and promoted.