This article seeks to clarify the concept of universal principles of legislation and to identify their constituent elements through a systematic review of the views of leading legal theorists. The importance of this inquiry extends to all areas of lawmaking, but it is especially significant in criminal law, where legislation directly affects individual rights and freedoms, public security, and the exercise of state coercion. Weaknesses in criminal legislation may therefore result in unjustified restrictions on liberty. Given the absence of a comprehensive and widely accepted definition of the principles of legislation in legal scholarship, this study applies content analysis and logical induction to the ideas of Jeremy Bentham, John Rawls, Lon Fuller, Friedrich Hayek, Charles Mitchell, John Holmes, and Jeremy Waldron. The findings indicate that, although these thinkers stress the importance of legislative principles, none offers a precise and comprehensive definition of the concept. However, their views reveal shared core elements that allow such principles to be understood as fundamental, general, normative, prescriptive, and rational rules that guide the legislative process toward laws that are just, efficient, clear, stable, and grounded in collective reason. This definition provides a useful framework for evaluating legislative quality and, in criminal law, for assessing the legitimacy and desirability of legislative policy.