Burr Henly, "Penumbra": The Roots of a Legal Metaphor, 15 Hastings Const. L. Q. 81, 83–84 (1987) (discussing origin of term from its original scientific meaning); Glenn H. Reynolds, Penumbral Reasoning on the Right, 140 U. Pa. L. Rev. 1333, 1336 (1992) (discussing how the Supreme Court has found "a right of privacy implicit in the logic and structure of the Bill of Rights").
Burr Henly, "Penumbra": The Roots of a Legal Metaphor, 15 Hastings Const. L. Q. 81, 83–84 (1987) (quoting Holmes, The Theory of Torts, 7 Am. L. Rev. 652, 654 (1873), reprinted in 44 Harv. L. Rev. 773, 775 (1931)).
Burr Henly, "Penumbra": The Roots of a Legal Metaphor, 15 Hastings Const. L. Q. 81, 84 (1987) (internal quotations omitted) (citing Webster's New Collegiate Dictionary 871 (9th ed. 1985)).
Burr Henly, "Penumbra": The Roots of a Legal Metaphor, 15 Hastings Const. L. Q. 81, 87 (1987) (describing Justice Holmes' references to "a protective penumbra created by certain provisions of the Bill of Rights").
Louis J. Sirico Jr., Failed Constitutional Metaphors: The Wall of Separation and the Penumbra, 45 U. Rich. L. Rev. 459, 478–79 (2011) (citing Montgomery v. Bevans, 17 F. Cas. 628, 632 (C.C.D. Cal. 1871) (No. 9735)); Henry T. Greely, A Footnote to "Penumbra" in Griswold v. Connecticut, 6 Const. Comment. 251, 252-53 (1989) (noting "its first use in 1871").
Sirico identifies Hanover Star Milling Co. v. Metcalf, 240 U.S. 403, 426 (1916) (Holmes, J., concurring), as the first appearance of the term in an opinion published by the Supreme Court of the United States. See Louis J. Sirico Jr., Failed Constitutional Metaphors: The Wall of Separation and the Penumbra, 45 U. Rich. L. Rev. 459, 479 (2011).
Burr Henly, "Penumbra": The Roots of a Legal Metaphor, 15 Hastings Const. L. Q. 81, 83–84 (1987) (discussing origin of term from its original scientific meaning); Glenn H. Reynolds, Penumbral Reasoning on the Right, 140 U. Pa. L. Rev. 1333, 1336 (1992) (discussing how the Supreme Court has found "a right of privacy implicit in the logic and structure of the Bill of Rights").