Definition
Intoxication, in law, refers to a condition in which a person's mental or physical faculties are substantially impaired by the introduction of alcohol, drugs, or other intoxicating substances into the body. The term carries different legal weight depending on context:
1. Criminal law — Intoxication is a condition that may, under defined circumstances, negate the mental state (mens rea) required for a criminal offense, or bear on the degree of culpability. Whether voluntary or involuntary intoxication is raised, and which specific intent or general intent offense is charged, determines whether the defense is available at all.
2. Tort law — Intoxication can establish negligence or contributory negligence, bear on a party's capacity to consent, and in some jurisdictions trigger dram shop liability for those who furnished the intoxicant.
3. Contract law — A person who enters into a contract while sufficiently intoxicated may lack the legal capacity to contract, rendering the agreement voidable at the intoxicated party's election upon return to sobriety, provided the other party had reason to know of the incapacity.
4. Public intoxication — Many jurisdictions make it a separate offense to appear in a public place in a state of intoxication, independent of any other criminal act.
The medical and toxicological sense of the term — poisoning by any substance — is broader than how courts and statutes typically use it. In legal instruments, intoxication almost universally refers to alcohol or controlled substances unless the text expressly provides otherwise.
---
Common Language
Modern common usage (Wiktionary): A poisoning by a spirituous or narcotic substance; the state of being intoxicated or drunk; a high excitement of mind rising to enthusiasm, frenzy, or madness.
Historical common usage (Webster's 1913): A poisoning by spirituous or narcotic substance; the state of being intoxicated or drunk; inebriation; ebriety; drunkenness; also, a high excitement of mind — "that secret intoxication of pleasure."
The gap that matters for researchers: The common and medical meaning of intoxication encompasses poisoning by any substance — a doctor might describe a patient as experiencing carbon monoxide intoxication or acetaminophen intoxication. Legal usage is narrower and more specific: statutes, indictments, and jury instructions ordinarily mean alcohol or drug-induced impairment. When reading older legal texts that use "intoxication" in a general poisoning sense, confirm whether the author is drawing on the clinical meaning or the legal one, as the distinction can affect how defenses and liability rules apply.
---
Common Confusion
Intoxication is sometimes used interchangeably with drunkenness in older sources, but the terms are not synonymous in modern law. Drunkenness historically implied alcohol specifically and often carried moral or behavioral connotations. Intoxication is the broader, more clinically neutral term now standard in statutes, model codes, and jury instructions, encompassing alcohol and other substances. Bouvier's directs readers to "Drunkenness" rather than maintaining a separate entry — a useful reminder that pre-twentieth-century legal dictionaries built their vocabulary around alcohol, and modern drug-related intoxication defenses must be researched separately in contemporary sources.
Voluntary intoxication and involuntary intoxication are frequently confused as mirror-image defenses. They are not: involuntary intoxication (where the person did not knowingly ingest the substance, or was coerced) is treated far more favorably and may excuse conduct entirely, while voluntary intoxication is a limited defense available only to negate specific intent in most jurisdictions.
---
Recognized Forms
/SUBTYPES
Voluntary intoxication — Self-induced impairment, knowing that the substance is intoxicating. The majority rule limits its use as a defense to specific intent crimes.
Involuntary intoxication — Impairment caused without the person's knowledge or consent, or by medically prescribed substances taken as directed. More broadly recognized as a defense and, in some formulations, treated analogously to the insanity defense.
Pathological intoxication — An extreme and atypical reaction to a small quantity of alcohol, producing a state grossly disproportionate to the amount consumed. Recognized in some jurisdictions as a subcategory of involuntary intoxication when the person had no prior reason to anticipate the reaction.
---
Why It Matters in Research
The most important navigational point is that intoxication research branches sharply depending on whether you are in criminal, contract, or tort law — the defense structures, elements, and outcomes are distinct, and blending sources across these contexts produces confusion.
In criminal law research, the Model Penal Code's treatment of intoxication (§ 2.08) is a useful organizing framework and has influenced many state codes, but significant variation remains. Some states have abolished voluntary intoxication as a defense altogether following high-profile cases; researchers must confirm current statutory status rather than relying on common law rules or treatise summaries.
Historical sources require care because the vocabulary evolved. Earlier cases and dictionaries focus almost entirely on alcohol. Modern statutory intoxication includes narcotics, prescription drugs, and other controlled substances, and some statutes specifically address whether prescribed medications taken as directed constitute voluntary intoxication. When researching period sources (pre-1970s), expect gaps on drug intoxication.
The public intoxication offense is often governed by local ordinance rather than state statute, making it under-indexed in standard legal research databases. Municipal codes and local court records may be essential sources.
In contract law, the standard for intoxication-based incapacity is high — courts do not void contracts for mere impairment. The condition must be severe enough that the person did not understand the nature and consequences of the transaction. Researchers should look to restatement provisions alongside case law, as judicial decisions vary considerably on what level of impairment satisfies this threshold.
Cross-corpus connections: the criminal defenses (voluntary and involuntary intoxication) connect to mens rea and the insanity defense; the contract dimension connects to the broader capacity-to-contract framework that also governs minors and mental incapacity; the public intoxication offense connects to status crimes and proportionality questions in criminal law.
---
Historical Dictionary Support
Bouvier's offers no independent entry, redirecting entirely to Drunkenness — a telling structural choice reflecting the era's vocabulary. Researchers using Bouvier's to trace intoxication doctrine should read the Drunkenness entry and recognize that most of its content addresses alcohol rather than the broader modern conception.
Black's (2nd Ed.) is more explicit about the tension: it notes that while the technical meaning of intoxication encompasses any poisoning of the human system, popular and legal usage restricts the term to alcohol-induced impairment. The entry expressly states this narrower reading governs "statutes, indictments, etc." — a useful signal for researchers interpreting nineteenth-century legal instruments.
Neither historical dictionary addresses drug intoxication in any substantive way, which is not a deficiency so much as a reflection of the legal landscape at the time. The framework for non-alcohol intoxication defenses developed primarily in the twentieth century, well after both sources were compiled. Researchers relying solely on historical dictionaries for intoxication doctrine will find the alcohol framework reasonably well documented and drug-related doctrine entirely absent.
---
Jurisdictional Note
Voluntary intoxication as a criminal defense varies significantly by state. Several states have legislatively eliminated or severely curtailed the defense in response to public pressure following specific cases; others retain a robust specific intent framework. Federal courts apply their own standards. Researchers should not assume the common law rule survives in any given jurisdiction without checking the current statute.
---