Definition
In Scots law, *poustie* means power or legal capacity — specifically, the mental and physical capacity of a person to perform a legally valid act, such as executing a deed or will. The term appears most prominently in the phrase *liege poustie*, which refers to a person being in full legal and bodily capacity: alive, of sound mind, and not on their deathbed. A deed or conveyance made while the grantor is in *liege poustie* carries greater legal presumption of validity than one made in contemplation of death (*in articulo mortis*).
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Common Language
**Modern common usage (Wiktionary):** Power, authority, strength, health.
**Historical common usage:** No Webster's 1913 entry recorded; the term did not enter general English usage.
The gap here is narrow but worth noting: in ordinary usage the word suggests physical strength or vitality generally. In Scots law, *poustie* carries a precise legal meaning tied to transactional capacity — the question is not merely whether a person was healthy, but whether they had the full legal power to bind themselves or dispose of property in a manner that cannot be challenged by their heirs.
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Common Confusion
*Poustie* is sometimes loosely equated with testamentary capacity, but the concepts are not identical. Testamentary capacity concerns mental competence to make a will. *Poustie*, particularly in the compound *liege poustie*, encompasses both mental soundness and the absence of the deathbed condition that would otherwise bring the *mortis causa* rules into play. A grantor might have testamentary capacity while no longer being in *liege poustie* if they are, for example, gravely and terminally ill at the time of executing an *inter vivos* deed.
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Why It Matters in Research
*Poustie* is a term of Scots law exclusively and will not appear in English common law sources. Researchers working with historical Scottish legal materials — particularly deeds, sasines, and testamentary disputes from the medieval period through the eighteenth century — will encounter it most often in the compound form *liege poustie*. Its importance is doctrinal: whether a grantor was in *liege poustie* at the time of a conveyance determined whether the deed was treated as an *inter vivos* act (generally irrevocable and binding on heirs) or was subject to challenge as a *donatio mortis causa* (a gift made in contemplation of death, which Scots law historically scrutinized more closely for fraud against creditors and heirs).
Researchers should be alert to two things. First, the spelling varies significantly across historical records: *poustie*, *pouste*, *pousti*, and Latinized forms derived from *potestas* all appear. Second, because Black's Law Dictionary treats this term briefly and directs readers to *liege poustie* for fuller treatment, the main doctrinal content lives under that compound headword, not here. Searching only for *poustie* in isolation will miss the bulk of the relevant legal discussion in both historical dictionaries and primary sources.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) gives the definition as simply "power" and notes its derivation from the Latin *potestas*, directing the reader to the entry for *liege poustie*. This is the only entry among the standard historical law dictionaries in the Law Mind corpus. The brevity of the standalone entry is characteristic: *poustie* functions almost exclusively as a component of the compound term, and historical Scots legal writers likewise treated it as a building block rather than an independent concept. The Latin derivation is uncontroversial and consistent across sources. No historical dictionary entry disputes the meaning; the absence of variation reflects the term's narrow, specialized use rather than any editorial consensus.
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Jurisdictional Note
*Poustie* is a term of Scots law with no counterpart in English common law or American law. It is relevant only in research touching Scottish legal history, Scottish private law, or comparative work on civil-law-influenced capacity doctrines.
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