This chapter offers a comprehensive and structured overview of the key theories explaining the origin and nature of law, tracing their development from mythological and religious conceptions to modern libertarian legal thought. Beginning with ancient beliefs in divine or supernatural sources of law, the chapter explores how early civilizations justified authority and legal norms through the will of gods. It then moves to patriarchal and paternalistic conceptions, examining how historical legal systems reinforced gender hierarchies and limited personal autonomy under the guise of care and protection. The organic theory likens society and the state to living organisms, with legal institutions functioning like interdependent organs. Classical natural law and social contract theories are discussed as foundational rationalist frameworks, highlighting law’s moral underpinnings and its legitimacy through collective agreement. Legalist (positivist) and Marxist theories present contrasting views, portraying law either as a product of state authority or as an instrument of class domination. The psychological theory, developed by Petrażycki, redefines law as a psychological experience shaped by internal impulses and emotions. Finally, the libertarian theory emphasizes law as the institutionalization of formal equality, presenting it as the normative framework through which individual freedom is realized. The chapter equips readers with a nuanced understanding of how legal thought has evolved across time and ideologies, emphasizing the continued relevance of these theories in shaping modern legal systems, especially in post-Soviet contexts.