Definition
To deprave, in its legal sense, carries two related but distinct meanings depending on context.
1. To defame, vilify, or exhibit contempt for — specifically as applied to religious or official institutions. In English law, to "deprave" the Lord's Supper or the Book of Common Prayer was a criminal offense punishable by fine and imprisonment. The term here describes an act of public contempt or derision directed at a legally protected object, rather than a private slur against an individual.
2. More broadly, to corrupt, vitiate, or make morally worse — the sense underlying phrases like "depraved indifference" or "depraved heart" in criminal law. In this usage, deprave describes the quality of a mental state or moral character rather than an affirmative act of speech.
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Common Language
Modern common usage (Wiktionary): To speak ill of; to depreciate; to malign; to revile. Also: to make bad or worse; to vitiate; to corrupt.
Historical common usage (Webster's 1913): "To speak ill of; to depreciate; to malign; to revile. [Obs.]" and "To make bad or worse; to vitiate; to corrupt."
Webster's labels the "speak ill of" sense obsolete, and that obsolescence is precisely where legal and common usage diverge. In ordinary modern English, "deprave" survives almost exclusively in its moral corruption sense — "depraved" describes a person's character. In historical legal English, the term retained its older meaning of contemptuous speech or public vilification directed at protected institutions. A researcher reading a historical English criminal pleading who encounters "deprave" should not assume it refers to moral corruption of a person; it may instead describe a verbal or written act of contempt against a religious or civil authority.
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Common Confusion
"Deprave" and "deprive" are phonetically similar and occasionally transposed in older manuscript sources and early typeset legal reports. They have no shared meaning. Separately, "deprave" in its moral corruption sense is often treated as synonymous with "corrupt" or "vitiate," but in formal criminal law the compound phrase "depraved" functions as a term of art describing a specific mental state (recklessness exhibiting extreme indifference to human life), not simply general wickedness. Treating "depraved" as a loose synonym for "evil" or "immoral" will cause researchers to misread jury instructions and appellate opinions discussing depraved heart murder.
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Why It Matters in Research
Researchers will encounter "deprave" across at least two distinct legal contexts, and conflating them produces analytical error.
In historical English ecclesiastical and criminal law sources, "deprave" almost always means contemptuous speech or written vilification directed at official religious forms — the Lord's Supper, the Book of Common Prayer, or similar protected objects. This usage is a relic of English penal statutes protecting state religion and has no direct American counterpart. When it appears in historical digests, treatises, or reporters, it is functioning as a term of religious-criminal art. Stephen's Criminal Digest (the source both Black's and Rapalje cite) is the key secondary reference for understanding the English offense.
In American criminal law, "deprave" survives primarily as the root of "depraved" in the phrase "depraved heart" or "depraved indifference," a mental state standard for second-degree murder in many jurisdictions. This is a live doctrinal area with an active body of case law. The term here has migrated entirely away from speech acts and into the assessment of recklessness and moral culpability. Corpus searches for "deprave" alone will miss much of this material, which will appear as "depraved indifference" or "depraved heart" in headnotes and opinions.
Historical sources are thin on the American criminal law usage because the "depraved heart" doctrine developed primarily through case law rather than statutory codification. Black's and Rapalje both define "deprave" in its English ecclesiastical sense only — neither entry captures the American criminal law evolution. Researchers using historical dictionaries alone will get an incomplete and potentially misleading picture of how the term functions in modern American courts.
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Historical Dictionary Support
Black's Law Dictionary and Rapalje & Lawrence are in close agreement: both define "deprave" as to defame, vilify, or exhibit contempt for, and both anchor the legal meaning to the English offense of depraving the Lord's Supper or the Book of Common Prayer. Both cite Stephen's Criminal Digest as authority. The entries are nearly parallel, suggesting a shared source or direct borrowing.
What both sources miss entirely is the parallel and ultimately dominant American usage rooted in moral corruption — the "depraved" in "depraved heart murder." This is not an oversight unique to these dictionaries; the doctrine's development through common law courts rather than legislative definition meant it was slow to appear in legal reference works. Neither entry would be useful to a researcher working on an American homicide case involving depraved indifference.
Webster's 1913 is instructive precisely because it labels the "speak ill of" sense obsolete even as of 1913, confirming that the English ecclesiastical legal meaning was already archaic in common usage by the time American criminal law was generating its own body of "depraved heart" doctrine.
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Encyclopedia Cross-Reference
Homicide — Depraved Heart / Depraved Indifference Murder (The Law Mind Criminal Law Encyclopedia)
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