First of all, on the surface on which I am going to paint, I draw a rectangle of whatever size I want, which I regard as an open window through which the subject to be painted is seen…
Leon Battista Alberti, cited in Martin Heidegger’s “The Age of the World Picture”, 1938
Lines have enormous power. The moment you connect two points, you’re making a claim about how space should be organized, and about who gets to organize it. At the very least you’re describing an inside and an outside, and usually much more. Draw a line on the ground and you arrive at the idea of private property. Draw a line on a map and you have a border. Around the world and you have something like an equator, dividing hemispheres and securing latitudes. Around an image, a line becomes a frame. Meeting in that same image, lines go further and give us linear perspective: the picture that is the window that is the world.
It’s through the act of drawing lines that space enters history, as Reviel Netz (2004) has pointed out before me. Lines happen and they keep on happening, cut right into the earth and the psyche. Because they run so deep they risk being experienced as injury, they require regular reinforcement to sustain them. Properties get fences and borders get guards. Fiber-optic cables are plunged into the ground beneath freeways; roads run where railways passed before them; wagons before that, and feet earlier still. That phenomenon of retread is even called path dependency, naming the durability of lines of the imagination.
The horizon is a line too, although it isn’t a line like the others. In some ways it’s the ur-line, the first line, from which the rest derive meaning. The horizon “defined the limits of communication and understanding,” Hito Steyerl (2011) writes. Beyond it there was only “muteness and silence” but within it, “things could be made visible.” She’s talking specifically about the centrality of horizons to the project of colonialism, both as a means of navigation and a fantasy of infinite territorial expansion. Inherent in any optics of expansion, she suggests, are the principles of intelligibility and possession. To see is to know and to grasp and to hold. The ephemera of horizon-work testify to this: in maps, paintings and photographs, sight approximates and enables ownership. The world must be represented in order to be conquered, and sometimes these are the same scheme. Unlike other lines, then, horizons are not just how space is ushered into history. They are history-making.
Renée Holleman’s A Brief History of the Horizon takes its cue from a figure in whom the ambitions of colonialism converge. Thomas Baines - painter, explorer, amateur scientist – was a man driven by horizons. As an artist his vast oeuvre reflects the high-noon of British imperialism in Africa, capturing the covetous white gaze that constituted real and imaginary geographies. For Holleman, Baines is also a vanishing point, disappearing the violent, racist dispossessions that gave South Africa’s its modern landscape just as he lends dimension to a view of the world that has since been hard to shake. She reminds us that sightlines, like the lines on maps, carve up space and leave indelible marks.
By tracking the robustness of a mode of perception over time, A Brief History catalogues these marks and spaces, insisting that they too to be held up to inspection. At its core the show is an intensive study in the intertwining of sight, representation, mobility and place-making, all of which it refuses to untangle.
Anna Stielau, 2019
 Reviel Netz. Barbed wire: An ecology of modernity. Wesleyan University Press, 2004.
 Hito Steyerl, ‘In Free Fall: A Thought Experiment on Vertical Perspective’, e-flux 4, 2011, no 24, p 8