Trees and walls — these fixtures of landscape are so common the world over, and have been since time immemorial, that when we look at them, not only do we see them for what they are but for what they represent to our mind’s eye. Depending on the settings and circumstances, both trees and walls elicit countless thoughts and ideas: they are beautiful; they are imposing; they protect; they endanger; they provide; they restrict; they guide; they grow; they fall.
As familiar as we are with physical trees, we are just as familiar with how the structure of a tree – from the roots, up through the trunk, and extending out to the branches – has been used to represent the organization of all sorts of information, like the family tree.
As Manuel Lima points out in The Book of Trees: Visualizing Branches of Knowledge, we have Aristotle to thank for first conceiving an understanding of the universe based on a hierarchical scale, prompting Porphyry, a Greek philosopher greatly influenced by Aristotle, to organize this concept into something “resembling an arboreal construct,” known as the Porphyrian tree. While the tree had long been a spiritual touchstone in the cradles of civilization, it was Aristotle and Porphyry who established trees as an epistemological model that’s expanded over time because, according to Lima, they “embody a fundamental organizational principle that reflects the way humans like to look at the world.”
Lima’s thorough research is a testament to dendrolatry – “the veneration of trees” – but more importantly it is a studious history of how the physical tree has been utilized as a model with which to visually organize huge amounts of information in ways that are manageable, and surprising.
The earliest tree diagrams, many of them stunning works of art and information design, are figurative trees greatly dedicated to genealogy and religious studies. Though some figurative trees are put to uses of lesser callings, like “The Petroleum Tree,” which looks like it could have been pulled from an episode of The Simpsons. Produced in 1957 by the company that would become known as Mobil, this tree is rooted in crude oil and leafed by products like “fly spray,” “light house oil,” and “switch grease” – I wouldn’t want to eat the fruit from this tree. But as Lima makes clear with the book’s chapters, as the kinds of information being organized, and the quantity of it, expanded so too did the shapes of these trees. Lima writes: “Even though tree diagrams have lost some of the their lifelike features over the years, becoming ever more stylized and nonfigurative, many of their associated labels, such as roots, branches, and leaves, are still widely used.”
In the first edition of Charles Darwin’s On the Origins of Species, the only illustration is “the tree of life,” an “essential demonstration of [Darwin’s] evolutionary thinking and the theory of universal common descent.” It does not look like a tree, but it behaves like one, sprouting from the roots of eleven “hypothetical ancestral species” that branch out, “indicating subsequent varieties and subspecies.” Since the inception of the tree diagram there have been many takes on trees, from horizontal to multidirectional, hyperbolic ones, and icicle, mapping everything from biodiversity to the code structure of open-source software. Lima’s elucidating captions accompanying the bevy of illustrations document how the tree, vital to life as we know it on this planet, is also an indispensable tool for us to understand any sort of information we might want to organize and study.
Another organizational structure, which at first glance might not come off as nuanced as a tree, is a wall. But politics and art have long made the case for a wall’s physical and metaphorical significance and Keep Your Eye On the Wall: Palestinian Landscapes demonstrates through remarkable design and content how the Separation Barrier that cleaves the West Bank is dense with meaning.
Interestingly, in the book’s foreword, human rights activist and author Raja Shehadeh likens Noel Jabbour’s photographs of the barbed wire lining the Wall to a forest: “not one you would wish to explore, but one that declares the obliteration of what exists beyond it through an impenetrable matrix of lines and circles that hardly allows even light to shine through.”
The artists and writers who have contributed to this book, however, do force some light through the cracks in the Wall, illuminating aspects of this reality that are highly localized but also universal. They have much more to do with real people than imposing concrete. Yael Lerer writes of how “the Territories are . . . no longer divided only by walls and checkpoints, but subject to a sophisticated three-dimensional system of separation of which walls are only one element.” Taysir Batniji’s series of photographs of decaying death notices plastered to the Wall, in his words, “reflects on a double disappearance: of those who gained recognition through their images on posters, and of the disappearance of the posters themselves.” The same as the graphic elements of these photographs pull in the viewer so too do the broader concepts of martyrdom and objectification.
Fittingly, the concertina binding of Keep Your Eye On the Wall can be unfolded into a lengthy wall. This design decision not only enhances the metaphors at play throughout the entire book, but it also allows the photographs to be reproduced at sizes that convey the scale of the respective projects, all of which, on some level, speak to how the Wall eclipses individuals, robbing them of their individual identities in the name of political agendas.
In the hypnotizing short story “The Fence” Adania Shibli deftly describes how paranoia permits both a physical and psychic fence to be erected around her character, leaving him isolated from everything. Having left the heart of the city for its bucolic edges, the man finds solace in sunrise: “He would watch the first ray of light reach the top of the last tree in the row, gradually extend to the rest of the tree, then the adjacent trees, than the rest of the row.” But not even this simple pleasure spares him from the anxiety he has brought with him. The only to stifle it is by remaining inside all of the time, behind the fence he has built around himself.
Walls are not always just walls, and the same can be said of trees. These two books illuminate how investing importance in an object, not just for utilitarian purposes, but for the metaphors that we derive from them, can help us make sense of the world around us.