Metaphor as a Key to Critical Thinking
By Todd Harper

Students often encounter the discourse of our disciplines and their objects of knowledge as they would encounter a foreign language, whose terms and meanings seem alien. Many of these students learn by comparing and contrasting, placing objects within a class and then differentiating them. One particular site for comparing and contrasting, classifying and differentiating is the metaphor trope which is often ignored if not discouraged in academic discourse. By encouraging students to use metaphors within their writing and by using metaphor within classroom lectures, we can help students make connections and build bridges between what they do know and what they don’t.

By definition, metaphor is a trope (a figure of speech) comparing two terms by the verb “to be.” As a generic term, metaphor refers to both metaphor and simile. Used specifically, it is usually differentiated from simile—metaphor uses a direct comparison by the verb “to be,” while simile uses the comparative terms “like” or “as” to form a less direct comparison. For instance, “Academic discourse is a foreign language” is a metaphor, while “Academic discourse is like a foreign language” is a simile. The difference is a matter of degree rather than kind. Sometimes, the metaphor is made more direct by replacing the verb “to be” with a metaphoric verb, as in “Yesterday, I horsed around with my children.”

Setting aside the distinction between metaphor and simile, metaphor allows instructors to help students gain a clearer understanding of what we are trying to say. If we are introducing an unknown, a metaphor can help bridge a gap by linking it to what is known. For instance, “Light is a wave.” As a term within physics, light and the properties of light are difficult concepts for many students to imagine. By comparing those properties to the visual and kinetic metaphor of the wave, students can more easily visualize what otherwise might seem to them to be invisible.

Metaphors also help to contextualize concepts. For instance, the Watson-Crick process of discovery of the prototype human gene has often been called “the race for the double helix.” By linking the discovery with a race, students can see that the model for DNA was not discovered by Watson and Crick working all alone in a laboratory. Instead, the discovery involved an active competition with other scientists.

Finally, metaphors are often effective invention exercises. Students can discover material for their papers by noting the similarities and differences between the comparative terms. For instance, a former student wrote a paper on the “War on Drugs.” At first, the student had difficulty trying to focus on this extensive issue. The student finally resolved her problem by deciding to write on how the “war on drugs” fit the description of an actual war and how it didn’t.

Metaphors can be effective tools for teaching disciplinary concepts to students and for student writing. They can bring in the unknown by a comparison to the known, contextualize concepts, and work as sources of invention. As Clifford Geertz notes, metaphor exists at the very heart of disciplinary theories: “Because theory, scientific or otherwise, moves mainly by analogy, a 'seeing-as' comprehension of the less intelligible by the more (the earth is a magnet, the heart is a pump, light is a wave, the brain is a computer, and space is a balloon), when its course shifts, the conceits in which it expresses itself shift with it” (22). Quite possibly, though, their ultimate benefit to the classroom is that metaphors help students acquire a sensitivity to academic discourse by directing their attention to the tropes already implicit within academic language.

Works Cited
Geertz, Clifford. Local Knowledge: Further Essays in Interpretative Anthropology. New York: Basic Books, Inc. 1983.