In the modern jurisprudence of the United States Supreme Court, the controversy over the place of metaphor came directly into the spotlight in Griswold v. Connecticut. Justice Douglas, writing for the majority and relying in part on metaphoric reasoning for his argument, located a right to privacy in the penumbral area formed by emanations from specific guarantees in the Bill of Rights. The various opinions in Griswold represent a divide regarding the place of metaphoric reasoning in legal argument. Justice Douglas employs metaphoric reasoning, while several of his fellow justices either avoid it or reject it. Because the case has been pivotal in establishing a right to privacy, this division about the Court’s use of metaphoric reasoning has extended into the many commentaries on the case. Somewhat ironically, at about the same time that a number of commentators began to analyze, and disagree about, Douglas’s use of the penumbra metaphor, another group of thinkers began reexamining the place of metaphor altogether, both in language and in thought. This latter group asserted not only that metaphor was a common and ordinary feature of language, but that metaphor was also central to human thinking - part of the very stuff of thought. For them, metaphor is conceptual, and it lies at the heart of how we understand the world. At the level of thought, we can hardly avoid using metaphor. The conceptual soundness of Douglas’s use of the penumbra metaphor in Griswold has been called into question by several earlier authors. It may be that metaphors have some unspoken “rules” for usage and that Douglas violated some of them. This article takes a step in that direction, by revisiting and further exploring some of the ways in which metaphors work. Starting with classical rhetoric, metaphors have traditionally been regarded as a matter of style, but recent research indicates that their role in our understanding of the world lies much deeper. Metaphors work through complex systems of correspondences, involving the mapping of conceptual domains onto each other and relying on the entailments that arise from that mapping. The “rules” for metaphorical usage, then, no doubt run deep as well - into this mapping and its coherence. If such unspoken “rules” for metaphorical usage exist, then Douglas may have violated some of them with his penumbra metaphor - sound as his conceptual use of the metaphor may have been in other respects. Understanding the strengths, and perhaps the shortcomings, of the penumbra metaphor, then, can be a way of learning how to use metaphoric reasoning effectively in legal argument.
Penumbral Thinking Revisited: Metaphor in Legal Argumentation, 7 Legal Communication & Rhetoric: JALWD 155