The Rule of Legal Ignorance in Spanish Law: Relevance, Meaning, and Scope

The rule ignorantia juris non excusat constitutes a historical principle in Spanish law as a key pillar of the collective organization of the legal system. The rule embodies the assumption that the effectiveness of the laws cannot rely on subjective elements, such as knowledge or ignorance, interest or carelessness, but it is based on an objective and social component of the legal system aimed to ensure that the enforcement of the laws is general and unconditional. Today, it is still inspiring the legal system and expressly enshrined in Article 6.1 CC, but their meaning must be duly contextualized in the current exuberance of legislation and regulations. Last decades, continuous efforts have been made to enhance the publicity of laws, improve comprehensibility, and implement technological solutions aimed to ensure accessibility of legislation, case law, and public authorities’ decisions. This article traces the origin and the evolution of the principle in Spanish law and the current expressions and applications of legal ignorance in private law. The analysis of the state of the doctrinal debate and the latest case law invites two reflections. First, the excessive use of legal ignorance as an invalidating mistake as a tool to alleviate contractual unfairness, inadequate institutional practices, or commercial abuse blurs its contours, debilitates the principle of contract preservation, deteriorates legal certainty, and discourages transactions. Second, the regulation of increasing information duties as a strategy to attenuate the impact of legal ignorance is making preand contractual processes complex, overinformed, and formalistic, with the risk of inviting purely formal compliance.