Carnegie Mellon University

Charles Darwin’s Multimodal Scientific Invention

Author: Daniel Dickson-LaPrade
Degree: Ph.D. in Rhetoric, Carnegie Mellon University, 2016

This project examines multimodal invention in science, concentrating on the notebooks and writings of Charles Darwin. By tracing particular processes of invention through time, from the notebook page to publication, I am able to shed light on how shifts in modality—from sentences of prose to diagrams and back, for example—help scientists develop both innovative scientific explanations and novel argumentation, especially multimodal argumentation.

Though many rhetoric scholars have examined scientific invention, very little of this scholarship deals with multimodality. Even that scholarship which deals with multimodality typically deals only with visuals, and concentrates primarily on finished scientific texts. This project is valuable in examining in detail how shifts from one modality to another operate in scientific invention, from the earliest investigative phases to final publication.

I derive my method from work by Linda Flower and John Hayes (1980, 1981, 1984) on the writing process. Flower and Hayes argue that the writing process involves the iterative representation and re-representation of meaning over time. Eventually, some of these meaning representations come to take on more and more of the constraints of finished prose, until a finished text is produced. I analyze Darwin’s inventional process by concentrating on moments when Darwin re-represents meaning in a different modality, and examining what Darwin gains from each modal shift.

I will present the chapter from my dissertation in which I examine Darwin’s use of family-tree-like diagrams between 1837 and his 1859 book On the Origin of Species. I argue that by shifting from prose to tree diagrams and back, Darwin first develops novel insights about nature. Later, Darwin revises the diagrams themselves, making them into presentable depictions of his theory. Ultimately, repeated shifts between modalities even come to involve the large-scale rhetorical strategy of Darwin’s 1859 book. Thus, though the multimodal re-representation of meaning is constant in Darwin’s invention, the inventional process begins with theoretical innovation, continues with the development of rhetorically useful meaning representations, and culminates in the development of large-scale, multimodal rhetorical strategy which structures an entire text.