Definition
"In being" means existing or alive at a specific moment in time. The phrase is used as a term of limitation or reference in property law and future interests doctrine to identify persons who are legally recognized as living at the moment a particular legal event occurs — most commonly the creation of a trust, will, or other instrument conveying a future interest.
In its most consequential application, "in being" defines the measuring lives permitted under the Rule Against Perpetuities. An interest must vest, if at all, within a life or lives in being at the creation of the interest, plus twenty-one years. The persons who qualify as measuring lives must be ascertainable and alive — that is, in being — at the relevant moment.
A child conceived but not yet born (en ventre sa mère) may, in certain circumstances, be treated as in being, provided the child is subsequently born alive. This is a narrow but important exception: the law does not generally treat the unborn as persons for all purposes, but for the specific purpose of protecting vested interests and validating future interests under the perpetuities rule, courts have consistently extended "in being" to include viable gestating children where it benefits the interest at stake.
Common Language
Modern common usage (Wiktionary): "In being" in ordinary English means simply existing or present; a state of existence as opposed to nonexistence.
Historical common usage (Webster's 1913): Webster's treats "being" as existence or the state of existing, with "in being" implying that something currently exists as opposed to having ceased or not yet come into existence.
The gap between common and legal meaning is narrow but technically precise. Ordinary usage of "in being" is intuitive — something either exists or it doesn't. Legal usage, however, attaches "in being" to a fixed legal moment and applies it to a specific doctrinal test. The question is not merely whether a person is alive in a general sense, but whether they were alive at the legally operative moment — the creation of the instrument. A person born the day after a trust is executed is not a life in being for perpetuities purposes, even though that person is indisputably alive.
Common Confusion
"In being" is sometimes loosely equated with "living" or "surviving," but these are not interchangeable in all contexts. "Surviving" implies outlasting another person or event; a person can be in being at the creation of an instrument but fail to survive the testator. "Living" is a present-tense biological description with no fixed legal anchor. "In being," by contrast, is retrospective and relational — it is always measured back to a defined legal moment. Researchers working with instruments drafted in plain language should be alert to drafters substituting these terms interchangeably, which can create ambiguity in perpetuities analysis.
Why It Matters in Research
The primary research significance of "in being" lies in its role within Rule Against Perpetuities doctrine, one of the most technically demanding areas of property law. Researchers must keep several navigational points in mind.
First, the common-law rule — to which "in being" belongs — has been substantially modified or abolished in many jurisdictions. When researching cases or instruments predating statutory reform (including wait-and-see statutes, the Uniform Statutory Rule Against Perpetuities, or trust law modernization allowing dynasty trusts), the classical definition of "in being" governs. Post-reform materials may use the phrase with a looser or residual meaning, or may have displaced it entirely.
Second, the treatment of unborn children as "in being" appears consistently in older case law and is worth tracking carefully. Courts in the nineteenth and early twentieth centuries developed specific rules for when gestation would suffice, and those rules are not uniform. Black's cites Ohio and New York authority for this proposition; researchers should not assume the rule transferred identically across jurisdictions.
Third, "in being" appears in contexts beyond perpetuities — including conditions precedent in deeds, contingent remainders, and certain insurance and trust instruments — and its meaning is consistent but the stakes of getting it wrong vary by context.
Fourth, older English and American authorities sometimes use the phrase without defining it, assuming the perpetuities context is obvious. Researchers reading nineteenth-century equity opinions should treat "lives in being" as a term of art requiring attention to which specific lives the court is counting and from what moment.
Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) defines "in being" concisely as "in existence or life at a given moment of time," immediately connecting it to the perpetuities context through the phrase "life or lives in being." Black's correctly notes the unborn child exception and supports it with citation to Phillips v. Herron and Hone v. Van Schaick — both real authorities establishing that gestation does not categorically exclude a person from being treated as in being.
The Black's entry is brief and functional, which reflects how the term was understood by practitioners of the period: as a settled phrase of art requiring little elaboration. What historical dictionaries do not address is the later doctrinal complexity created by perpetuities reform statutes, which either redefine or render obsolete the classical "lives in being" measurement. Researchers relying solely on historical dictionary sources will have an accurate picture of the common-law baseline but an incomplete picture of modern practice.
Jurisdictional Note
The significance of "in being" varies sharply by jurisdiction depending on whether the state has retained the common-law Rule Against Perpetuities, adopted a wait-and-see or savings statute, or enacted trust modernization legislation permitting perpetual or dynasty trusts. In jurisdictions that have abolished the traditional rule for trusts, "in being" retains relevance primarily for non-trust future interests and older instruments still governed by their original terms.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Rule Against Perpetuities; Future Interests; Contingent Remainder