Definition
Animus testandi is the intention to make a will. It is the mental element required for a valid testamentary act — the deliberate purpose, at the time of execution, to create a legally operative disposition of one's property to take effect at death.
The requirement is fundamental: a document that takes the form of a will but was not executed with genuine testamentary intent is not a will. The writer must understand that what they are doing is making a will, must intend the instrument to function as one, and must possess sufficient mental capacity to form that intent. Animus testandi therefore encompasses both the volitional element (the purpose to make a will) and the cognitive precondition (the mental capacity to hold that purpose).
Common Confusion
Animus testandi is sometimes loosely treated as synonymous with testamentary capacity, but the two are distinct requirements that can fail independently. Testamentary capacity is the legal threshold of mental competence — generally, that the testator understands the nature of a will, the extent of their property, the natural objects of their bounty, and how these elements relate. Animus testandi is the actual intention formed within that capacity: a person may possess full testamentary capacity yet still lack animus testandi if they signed a document without understanding or intending it to operate as a will (as in cases involving joke instruments, drafts mistakenly executed, or documents signed under misapprehension of their nature). Conversely, animus testandi cannot exist without testamentary capacity — an idiot or a person in a state of total delusion cannot form the requisite intent. The concepts are complementary but analytically separate.
Core Elements
Courts and commentators identify animus testandi as requiring:
1. Knowledge of the act. The testator must understand that the instrument being executed is a will — that it governs the disposition of property at death.
2. Present intention. The intent must exist at the moment of execution, not merely as a future plan. A document executed as a draft or experiment, without present intent that it operate as a will, lacks animus testandi.
3. Capacity to intend. Because intention presupposes a functioning mind, animus testandi cannot exist in the absence of testamentary capacity. The two requirements rise and fall together on the capacity question, even while remaining conceptually distinct.
Why It Matters in Research
Animus testandi appears most frequently in probate litigation over informal documents: letters, diary entries, handwritten notes, or instruments executed in unusual circumstances. Courts confronting these cases must determine whether the decedent intended the document to function as a will, making animus testandi the pivotal inquiry.
Researchers using historical sources should be alert to the following:
First, the term is more prevalent in older Anglo-American authorities and in civilian-influenced jurisdictions than in modern American cases, where courts often discuss the underlying concept without using the Latin phrase. Searching case law only by this term will miss substantial relevant material filed under "testamentary intent" or "testamentary purpose."
Second, the relationship between animus testandi and dependent relative revocation deserves attention. When a testator revokes an existing will in the belief that a new will is valid, courts may ask whether animus testandi attached to the revocatory act itself — a nuanced application that appears in older equity authorities.
Third, jurisdictions influenced by civil law (Louisiana, Quebec) may apply the concept with more doctrinal precision than common law states, where it tends to be absorbed into broader testamentary capacity analysis. Sources from these jurisdictions can offer useful doctrinal clarity unavailable in general common law digests.
Fourth, the question of conditional wills intersects with animus testandi: if a testator executes a document expressing intent to make a will only if a certain event occurs, courts must determine whether genuine testamentary intent existed at execution. Older treatises treat this problem directly under animus testandi.
Historical Dictionary Support
The three source dictionaries agree on the core definition — animus testandi is the intention to make a will — but differ in depth.
Black's is minimal, offering only a translation without doctrinal elaboration. It is a useful pointer but nothing more.
Bouvier's is the most practically useful historical source. It explicitly connects the requirement to the condition of an idiot who "can have no intention," making clear that animus testandi is simultaneously a volitional and a capacity requirement. The citation to Beach on Wills reflects a late-nineteenth-century American treatise tradition that integrated the Latin maxim into common law probate doctrine.
Burrill's adds a dimension the other two omit: the equation of animus testandi with "mind or capacity to make a will," drawing on Swinburne's and Perkins's authorities. This framing is more civilian in character and suggests that in earlier usage the distinction between intent and capacity was less sharp than modern doctrine draws it. Researchers relying on pre-twentieth-century authorities should be aware that older sources may conflate the two concepts in ways that create interpretive difficulty.
None of the three dictionaries addresses the evidentiary question of how animus testandi is proven — an omission that matters greatly in litigation. Modern courts typically look to surrounding circumstances, the formality of execution, statements made by the testator, and the document's own language to reconstruct intent.
Jurisdictional Note
The analytical separation between animus testandi and testamentary capacity is most clearly articulated in civil law and mixed jurisdictions. In common law states, courts frequently discuss testamentary intent as a component of the capacity inquiry rather than as a freestanding doctrine. Researchers working across jurisdictions should expect terminological and structural variation even when the underlying legal question is identical.