Taxonomy vs. iconography in data visualization

Posted on 02/03/2011 by


During college I worked at the University of Chicago Special Collections, where they keep the old, valuable, and/or particularly noteworthy volumes in the Library’s collection, among other things.  It is a very, very cool place (if you are in Chicago, it is definitely a place to see along with the Art Institute and MCA).  Well recently I came across a piece of their collection and accompanying analysis of the Essai d’une Distribution Genealogique des Sciences et des Arts Principaux, also known as that cactus chart (edit: alright, I made that up).  What really struck me was the accompanying analysis that looked at the development of visual genealogies as a matter of representing knowledge.  From Sigrid Weigel’s essay:

Taking Genesis and Kafka’s reflections as a point of reference, the Tree of Knowledge has been interpreted as the first genealogical tree, in the context of an examination of the link between the two trees of paradise, the Tree of Knowledge and the Tree of Life, in mediaeval representations: The tasting of the fruit from the wrong tree signifies the renunciation of immortality, but also the origin of all systems of kinship; the Tree of Knowledge is as it were the first family tree, not because the original parents ate from it, but because they began the project of the propagation of the human race in its shadow.

(Mediaval miniature by Berthold Furtmeyer: Baum des Todes und des Lebens, 1481 (depicting both trees in one). In: Roger Cook: The Tree of Life. Image for the Cosmos. New York 1974. 44)

He goes on to place these representations in the context of the development of biology as a discipline:

What needs to be considered here is an epistemic problem which has preoccupied the biological sciences since their emergence in the eighteenth century, the task namely of determining the relationship between the genetic constancy of genus or species and the variation or modification that is the condition of possibility for evolutionary change. If a species can on the one hand only be defined in terms of its difference from other species, its evolution can on the other hand only be conceived as development within time.

To Weigel, this presents a fundamental contradiction within the visualization of biological data, embodied in the conflict between taxonomy:

(Diderot: Systême figuré des connaissances humaines, Encyclopédie, 1851. In: Encyclopédie ou Dictionnaire Raisonné des Sciences, des Arts et des Métiers (1751). Reprint Stuttgart, Bad Cannstatt 1988. Bd. 1, o. S.)

and iconography:

(volume 1 of Pierre Mouchon, Table analytique et raisonnée des matieres contenues dans les XXXIII volumes in-folio du Dictionnaire des sciences, des arts et des métiers, et dans son supplément, (Paris, Panckoucke, 1780.)

Although it may appear that this conflict was resolved with the advent of a biological science with formalized methods of representation, there may be more to this.

In a sense, neither Mouchon nor Diderot won in the end–they just came to represent a new epistemic problem in the social sciences, namely the question of emergence.  What data visualization tools can represent in a way that conventional tabulation cannot are the emergent properties of social systems (more on this in a later post).  In this sense, I think that this 18th century conflict may have an analogy in today’s division between representation of data visually and in a more tabular, conventional form.  The images do not just signify a division in representation, but a fundamental cleavage in the methodologies and aims of social scientists.  As I argued in my post on data mining vs. visualization, the methods, tools, lexicon, journals, &c. of these two camps is diverging at a time when researchers should be coming together.