In a legal context, penumbra refers to the implied rights derived from the explicitly stated guarantees in the U.S. Constitution. The term was first used by Oliver Wendell Holmes. In his 1873 law review article “The Theory of Torts,” Holmes argued that new law should grow “in the penumbra between darkness and light, than to remain in uncertainty.”
In Griswold v. Connecticut (1965), Justice William O. Douglas opined that the Constitution implicitly guarantees certain rights despite not explicitly mentioning them. In this case, the Court struck down a Connecticut law banning the use of contraceptives, asserting that the law violated the right to privacy, which, although not specifically mentioned in the text of the Constitution, lies in the penumbra zone created by the Bill of Rights.
For example, the First Amendment implies freedom of association. The Fourth Amendment implies protection against invasion of privacy. Because of Griswold, the concept of penumbras has been most associated with the right to privacy. Besides contraception, the right to privacy was extended to abortion in Roe v. Wade (1973). However, it was later modified in Planned Parenthood v. Casey (1992) before it was finally overturned in Dobbs v. Jackson Women’s Health Organization (2022). The right to privacy also legalized interracial marriage in cases like Loving v. Virginia (1967) and same-sex marriage in Obergefell v. Hodges (2015).
Beyond privacy, the penumbra doctrine also has influenced interpretations related to bodily integrity and autonomy in personal decisions. The latter often includes rights related to family, marriage, and procreation. In essence, the "penumbra" in constitutional law signifies a dynamic area of implied rights, evolving with judicial interpretation and societal changes, ensuring the Constitution remains a living document responsive to contemporary issues and values.
[Last updated in August of 2024 by the Wex Definitions Team]