With abortion rights before the Supreme Court this term, I’ve been thinking about the metaphor that brought privacy—and by extension, reproductive health rights—under Constitutional protection. In Griswold v. Connecticut, Justice Douglas reasoned that enumerated individual rights “have penumbras, formed by emanations from those guarantees that help give them life and substance.” Douglas analyzed these penumbras to extend the zones of individual rights, frustrating dedicated textualists who saw no justification for them in the language of the Constitution.
It might be helpful to pause here and clarify exactly what a penumbra is. Hold an object up in front of a light source so that it casts a shadow on a nearby surface: at the center of the shadow will be its most focused darkness, its umbra; move your gaze out to the border of the shadow, to where it meets the light, and you will see a zone of unfocused shadow, a kind of half-light called the penumbra. In Douglas’s metaphor, a certain set of enumerated rights are the umbra and the unenumerated right to privacy is their penumbra, giving them life and substance.