Definition
The total renunciation of one's religion. In legal history, the term referred specifically to the formal abandonment of Christianity by a person who had previously professed it, treated under English law as a criminal offense. In modern legal contexts, apostasy rarely appears as a discrete common-law category; its relevance has shifted to constitutional and international human rights frameworks, where the freedom to change or renounce one's religion is a protected right in most liberal democracies — and a punishable act in several civil and criminal codes derived from Islamic jurisprudence.
Common Language
Modern common usage (Wiktionary): The renunciation of a belief or set of beliefs; specifically, the renunciation of one's religion or faith.
Historical common usage (Webster's 1913): An abandonment of what one has voluntarily professed; a total desertion or departure from one's faith, principles, or party; especially the renunciation of a religious faith.
The common and legal meanings converge closely here, but with a critical distinction: in ordinary usage, apostasy is a theological or social description carrying no legal consequence. In historical legal usage, it was a defined offense with penal consequences attached. A researcher reading older sources must recognize that the word carries an operative legal charge in historical materials that it entirely lacks in modern common usage.
Common Confusion
Apostasy is sometimes conflated with heresy and blasphemy in older sources. These are distinct legal categories. Heresy was the holding of beliefs contrary to established doctrine while remaining nominally within the faith. Blasphemy was the speaking of words offensive or contemptuous toward religion or the deity. Apostasy was the total exit from the faith — the more complete act. The three could overlap in practice and were sometimes prosecuted in sequence or together, but the historical dictionaries and Blackstone treat them as separate offenses with different elements and different forums of prosecution.
Why It Matters in Research
Researchers encountering apostasy in historical legal materials — particularly English common law sources from the seventeenth and eighteenth centuries — must understand that it operated as an actionable legal wrong, not merely a religious or moral characterization. Blackstone's Commentaries (Book IV, Chapter 4) classifies apostasy among offenses against God and religion cognizable by the temporal courts, noting the severe disabilities that attached.
In corpus research, the term will appear with very different valences depending on the era and jurisdiction of the source. Pre-nineteenth-century English materials treat it as a criminal matter. Nineteenth-century American materials largely strip it of criminal content due to the Establishment Clause, though social and ecclesiastical uses persist. Twentieth- and twenty-first-century materials reintroduce legal consequences primarily through international law and comparative constitutional sources — particularly materials from states where sharia-influenced penal codes remain in effect.
A researcher using the Law Mind corpus should be alert to this three-phase pattern: criminalized (English common law), largely inert (American constitutional era), and reactivated in a different legal system context (comparative and international law). Treating any single period's usage as representative will produce anachronistic readings.
The term also appears in ecclesiastical law materials in connection with clerical discipline, where apostasy by a member of a religious order carried distinct canonical consequences separate from civil law treatment. These two threads — civil/criminal and ecclesiastical/canonical — run in parallel and should not be conflated.
Historical Dictionary Support
Bouvier defines apostasy as the total renunciation of one's religion, noting that it was formerly the renunciation by a Christian of Christianity, was considered a crime in early history, and was punished accordingly, citing Blackstone (4 Bl. Comm. 43). The entry is brief, as is characteristic of Bouvier's treatment of terms whose legal force had largely dissolved by his time.
Bouvier's present-tense opening ("total renunciation of one's religion") reflects the general descriptive use of the term, while the historical note signals that the criminal valence was already receding. What Bouvier does not address is the jurisdictional survival of apostasy as a legal category in non-English legal systems — a significant omission for any researcher working across comparative law materials. The Standard Dictionary reference in Bouvier's entry points to contemporaneous general usage, reinforcing that by the mid-nineteenth century the term was being treated as primarily definitional rather than operative in American law.
No other source dictionaries were available for synthesis in this entry. Researchers should supplement Bouvier with Blackstone directly for the common law criminal treatment, and with canon law sources for ecclesiastical dimensions.
Jurisdictional Note
In the United States and most common law jurisdictions, apostasy carries no civil or criminal legal consequence; any such law would face substantial First Amendment or analogous constitutional challenge. In a number of states with Islamic law provisions — including Iran, Saudi Arabia, and others — apostasy remains a criminal offense, in some cases carrying capital punishment. Researchers working in comparative law, international human rights, or conflict-of-laws contexts must account for this divergence explicitly.