Definition
Latin: "part of the bowels of the mother." A common law maxim describing an unborn child as legally inseparable from — and constituting a part of — the body of its mother. The phrase captures the foundational common law position that, prior to live birth, a fetus possessed no independent legal personality. As a corollary, injuries sustained by the mother that also harmed the unborn child were treated in law as injuries to the mother alone, not to a separate legal person.
Common Confusion
PARS VISCERUM MATRIS is sometimes loosely equated with the proposition that the unborn child has no legal rights whatsoever under common law. This overstates the doctrine. Even at common law, the fetus was accorded certain contingent protections — most notably in the law of property, where a child en ventre sa mère could take an interest under a will or deed if subsequently born alive. The maxim describes the absence of independent legal personality for tort and criminal law purposes, not a complete legal invisibility across all fields.
Why It Matters in Research
This phrase is essential context for any historical research into the legal status of the unborn. It explains why early common law courts rejected wrongful death or personal injury claims brought on behalf of a stillborn child or a child injured in utero — the logic being that no legally cognizable separate person had been harmed. Researchers tracing the evolution of prenatal injury doctrine, fetal homicide statutes, or abortion jurisprudence will encounter this maxim as the baseline from which later law departed.
The phrase also appears in historical equity and property contexts, where courts wrestled with exactly how far the fiction of the unborn child's existence could be extended for the child's benefit. The tension between pars viscerum matris (the child as part of the mother) and the fiction that a child en ventre sa mère is born for purposes favorable to it runs throughout equity jurisprudence, and researchers should expect to find courts reasoning in both directions within the same era.
Researchers working with 19th- and early 20th-century materials should be alert to the transitional period when American courts began allowing prenatal injury claims, often by explicitly rejecting or limiting the reach of this maxim. The phrase itself becomes a marker: its presence in an opinion signals adherence to strict common law tradition; its absence or rebuttal signals a jurisdiction moving toward recognition of the fetus as a party capable of holding legal rights in its own right.
Because the term is Latin and appears almost exclusively in common law treatises and older case law, it will not appear in statutory texts. It is a creature of judicial reasoning and doctrinal shorthand, not legislative vocabulary.
Historical Dictionary Support
Black's Law Dictionary records the phrase briefly and accurately: "Part of the bowels of the mother; i.e., an unborn child." The entry is definitional rather than analytical, which is characteristic of Black's treatment of Latin maxims — it identifies the phrase without tracing its doctrinal consequences.
Historical legal dictionaries generally do not engage with the contested edges of the doctrine: they present it as settled, when in fact common law courts were simultaneously applying the contradictory fiction that a child en ventre sa mère is considered born whenever the child's own interests require it. No historical dictionary entry surveyed flags this internal tension, which is a meaningful gap for researchers who might otherwise assume the common law position was uniform.
Jurisdictional Note
The maxim originates in English common law and was received into American jurisprudence. American courts progressively departed from its strictest applications across the 20th century, particularly after the mid-century shift toward allowing tort claims for prenatal injuries. Its operative force today varies substantially by jurisdiction and legal context.