The series Spotlight on Good Writing highlights techniques used in public-facing writing that are widely applicable to writing of all kinds, including research papers and expository essays written by students.

This post focuses on one approach to writing an introduction.

Introductions function in different ways. Some provide a hook, a statement that makes readers want to find out more; others present a claim, or thesis, that will be advanced in the rest of the piece. Introductions may inform, but they can also entertain; the introduction to Joshua Rothman’s New Yorker essay “Daniel Dennett’s Science of the Soul” does both by telling a story and using a metaphor.

A Story Can Inform Readers

Rothman’s essay profiles the philosopher Daniel Dennett, who has worked to explain consciousness in humans and other forms of life. In his introduction, Rothman gives readers some background on the subject of consciousness by telling a story about life’s origins that is based on a scientific model:

Four billion years ago, Earth was a lifeless place. Nothing struggled, thought, or wanted. Slowly, that changed. Seawater leached chemicals from rocks; near thermal vents, those chemicals jostled and combined. Some hit upon the trick of making copies of themselves that, in turn, made more copies. The replicating chains were caught in oily bubbles, which protected them and made replication easier; eventually, they began to venture out into the open sea. A new level of order had been achieved on Earth. Life had begun.

In this passage, Rothman presents complex ideas in a way that is easy to grasp. By using terms like “chemicals,” “chains,” and “oily bubbles,” he avoids scientific jargon that might make readers reach for the dictionary—or run for the hills. He makes his summary entertaining by treating the chemicals as characters in the story who perform actions and change over time. The phrase “some hit upon the trick” supports this effect by suggesting that the chemicals are striving toward a goal. To give readers the feeling of progression that they might expect from a story, Rothman starts with short sentences, switches to longer ones, and then resumes using short sentences at the end of the passage. 

A Metaphor Can Help Illustrate a Complex Idea

Rothman goes on to summarize the development of life up to the emergence of humans, and he introduces the concept of evolution by drawing on a well-established metaphor, the tree of life:

The tree of life grew, its branches stretching toward complexity. Organisms developed systems, subsystems, and sub-subsystems, layered in ever-deepening regression. They used these systems to anticipate their future and to change it. When they looked within, some found that they had selves—constellations of memories, ideas, and purposes that emerged from the systems inside. They experienced being alive and had thoughts about that experience. They developed language and used it to know themselves; they began to ask how they had been made.

Rothman uses the image of a tree to suggest outward growth, as of the tree’s branches away from the trunk, or of organisms away from their simple origins and “toward complexity.” This use of the image is conventional, since the term “tree of life” often refers to a scientific diagram of how organisms have evolved (Zimmer). But in a twist, Rothman also uses the metaphor to suggest inward growth, as of the “systems, subsystems, and sub-subsystems” that living beings developed over time. This inward growth leads, in the story, to the development of mental activity (“memories, ideas, and purposes”) and human consciousness. Rothman’s metaphor provides a nice transition to the rest of the essay by suggesting the possibility of mapping this inner development, which is exactly what Dennett does in his work. 

An Introduction Should Support What Follows

The story that Rothman tells in his introduction reflects Dennett’s perspective on the origins of human consciousness. By presenting that perspective and using a metaphor to make it easier to grasp, the introduction equips readers to understand Dennett’s philosophy when it is discussed later in the essay. In general, an introduction should support the material that follows it by giving readers the information they’ll need to understand the rest of the piece. If you begin an essay with a story, make sure that the story illuminates or otherwise furthers your argument. 

Works Cited

Rothman, Joshua. “Daniel Dennett’s Science of the Soul.” The New Yorker, 20 Mar. 2017,

Zimmer, Carl. “Scientists Unveil New ‘Tree of Life.’” The New York Times, 11 Apr. 2016,

Photo of Michael Simon

Michael Simon

Michael Simon is associate editor at the MLA. He received an MFA in poetry from Columbia University and a BA in comparative literature from Brown University. Before coming to the MLA, he worked as an editor for several academic publishers.