Definition
In legal usage, "appreciate" carries a specific cognitive meaning distinct from its everyday senses. To appreciate, in law, means to understand, recognize, or comprehend the nature, quality, or significance of something—particularly one's own conduct, circumstances, or relationships. It denotes not mere awareness but a substantive grasp: the capacity to evaluate and estimate correctly.
The term appears most prominently in two legal contexts:
1. Criminal law / mental state: A person "appreciates" the nature and quality of an act, or the wrongfulness of conduct, when they have genuine understanding of what they are doing and why it matters legally or morally. This is the operative language in many formulations of the insanity defense and in assessments of diminished capacity.
2. Relational understanding: As Bouvier's records, to appreciate one's relation to another means the ability to estimate justly the nature of that relationship—used in competency and consent contexts, such as whether a person understands their familial or legal relationship to another party.
A third, financially oriented meaning—an asset's increase in market value over time—exists in law but functions as ordinary economic description rather than a term of art. It appears in property, tax, and marital dissolution contexts without specialized legal elaboration.
Common Language
Modern common usage (Wiktionary): To be grateful or thankful for something; to view something as valuable; to be fully conscious of or aware of something; to increase in value.
Historical common usage (Webster's 1913): To set a price or value on; to estimate justly; to be sensible of; to raise the value of, as opposed to depreciate.
The gap between common and legal meaning is meaningful in one direction: the everyday sense most speakers reach for first—gratitude—is almost entirely absent from legal usage. When a legal document, jury instruction, or competency standard asks whether a person "appreciates" something, it is asking about cognitive comprehension, not emotional thankfulness. Researchers reading historical legal materials should also note that Webster's 1913 preserves the estimative sense ("to set a price or value on; to estimate justly") that aligns closely with how the term was used in early legal contexts, and that connection is not coincidental.
Common Confusion
"Appreciate" is occasionally conflated with "understand" in legal drafting and judicial opinions, but the two are not identical. "Understand" can describe surface-level awareness; "appreciate" in law typically demands a deeper, more evaluative cognition—the ability to recognize significance, not merely to perceive facts. This distinction matters most in competency determinations and insanity defense standards, where courts have held that a defendant may technically "understand" an act while failing to "appreciate" its wrongfulness or consequences.
Why It Matters in Research
The cognitive sense of "appreciate" is load-bearing language in mental competency law. Researchers working with insanity defense materials will encounter the term in standards derived from the Model Penal Code's formulation, which asks whether a person, as a result of mental disease or defect, lacks substantial capacity to "appreciate" the criminality of their conduct—a deliberately chosen word that courts have distinguished from the stricter M'Naghten "know" standard. Reading historical sources that predate the MPC requires care: older materials may use "know," "understand," and "appreciate" loosely or interchangeably, without the doctrinal weight each carries in modern usage.
In the relational-understanding context Bouvier records—the ability to appreciate one's relation to another person—researchers will find the term in older competency, testamentary capacity, and guardianship materials. The illustration Bouvier gives (a father's relation to his daughter) reflects the kind of relational orientation courts historically examined in determining whether a person was legally capable of making decisions involving others.
For property and tax research, "appreciation" (the noun form) functions as ordinary economic vocabulary and does not trigger the cognitive analysis above. Researchers should not import the mental-state analysis into financial contexts where the term simply describes value increase.
Cross-corpus alert: The term bridges criminal law doctrine, competency and guardianship materials, and family law—researchers should expect it to appear in very different doctrinal neighborhoods, each with its own freight.
Historical Dictionary Support
Bouvier's is sparse on this term, offering a single illustrative proposition drawn from secondary authority: to appreciate one's relation to another is to be able to estimate justly the nature of that relationship. The definition is functional rather than analytical, and Bouvier does not address the criminal law usage at all—an absence that reflects the pre-MPC moment in which the dictionary was principally compiled.
Webster's 1913 is more useful as historical context. Its primary definition—"to set a price or value on; to estimate justly"—captures the evaluative core that migrated into legal usage. The sense of estimation and just valuation is precisely what courts mean when they ask whether a person appreciates the nature of an act or a relationship. Webster's also records the financial meaning (raising value, opposed to depreciate) and the sensory/perceptual meaning ("to be sensible of"), both of which appear in legal materials in their respective contexts.
Neither Bouvier's nor Webster's 1913 anticipates the full modern legal usage, particularly the specific role the term plays in mental state doctrine following the Model Penal Code. Researchers relying solely on historical dictionaries for this term will find partial coverage at best.
Jurisdictional Note
The cognitive "appreciate" standard in criminal law varies by jurisdiction. States following MPC-influenced insanity formulations use "appreciate" as the operative term; states retaining M'Naghten use "know." A few jurisdictions have abolished the insanity defense or modified it significantly. The word's presence or absence in a jurisdiction's standard is itself a doctrinal signal worth noting.