Ramon Llull, Prima Figura, Ars Magna, 1305
Mark Johnson, philosopher and theorist in the field of embodied cognition, employs the figure of the line recurrently as the main component of visual schemata. For embodied cognition, the theory which demonstrates how our physical experience of the world profoundly influences abstract thought, schemata are structures which are extracted from bodily experiences and translated as cognitive instruments which our brain employs to convey meaning. The recurring schemata of “path”—the physical experience of moving from one place to another—is thus represented by a simple line and translates in cognition in the idea of connection, the way two entities relate one another1.
The line which connects dots and thus establishes immediate social relations between data, concepts, geographies appears as the visual metaphor of the network (the central figure in contemporary information-based society). The multiple lines defining a network materialise human ability to relate subjects and construct knowledge out of isolated objects, while “moving” from one concept to another.
The work of Catalan polymath Ramon Llull (1232–1315), considered among the ancestors of formal systems of logic and even of computation and artificial intelligence, constitutes a precedent in the visual construction of relationships through multiple lines shaping a network.
Llull’s Ars generalis ultima (“The Ultimate General Art”) or Ars Magna included paper-based mechanisms aiming to create new knowledge from the connection and combination of different concepts. In the first illustration of the Ars, nine points equidistant on a circumference are all connected through similar lines. This system allows all the words written beside a rim to associate mutually. As metaphors of multiple paths, the lines materialise here the active role of the various terms and the way they interact in a dynamic system of relationship.
Llull initially conceived the Ars Magna as a device destined to the conversion of Muslims through the logics of Christian faith. However, the work progressively revealed an intrinsic capacity of acting as a “logical machine:” an apparatus able to produce knowledge in different fields through multiple combinations of notions. Through the symbolic potential of the line, Llull constructed the very first demonstration that a device can imitate human thought.
Based on Llull’s previous discoveries, Jesuitic polymath Athanasius Kircher developed various combinatory systems capable of generating all possible combinations from a finite collection of elements. Such techniques applied to the composition of aleatoric music, the description of alchemic tables of transformation, the construction of a language. When the lines intertwine, they draw figures whose striking visual qualities reveal Kircher’s aesthetic preoccupations.
Athanasius Kircher, “Combinationis Linearis”, in Ars Magna Sciendi Sive Combinatoria, 1669
When, in 1666, Gottfried Leibniz wrote his youthful work Dissertatio de arte combinatoria, he was inspired by Ramon Llull’s Ars Magna. Despite lately considering his text as immature, the Ars combinatoria constituted the philosopher’s accessway to the world of logic. In this work, all concepts derive from combinations of a small number of simple notions. A series of lines connecting basic concepts is again the figure which defines the intellectual operations. However, the lines are no longer just pure connectors; here, they get sufficiently thickened to include the kind of relationship they are supposed to symbolise (contraria, possibilis, summa). The lines do not lie on the same plane as in Llull’s figures, but they are superposed to construct an actual tissue of relationships.
Gottfried Leibniz, Dissertatio de arte combinatoria, Frontispiece of the book, 1690
All these historical figures represent early attempts to exteriorise human thought and logic through simple devices based on the ability of the line to act as a connector. Or, as Mark Johnson implied, to translate figuratively the act of walking from one place to another into the conceptual operation of relating notions to conjure up concepts. The visual appearance and intrinsic logic of those early devices resurfaced in the symbolic representation of the network, a figure made of interconnecting lines, which became widespread with the amplification of communication infrastructures. In the network, more points are connected by more lines, intersecting and transmitting information on different scales. The basic schemata of the path turned into the universal metaphor of how a multiplicity of things communicate and eventually produce a world-wide brain.
Such a cognitive analogy would become literal through the model of the “artificial neural network”, the typical representation of computing systems inspired by the biological neural networks in the human brain. ANNs visualisations are an attempt to simulate the architecture of the human brain to improve the performances of conventional algorithms. The points in the network represent artificial neurons and the lines (here, called edges), act like the synapses in a biological brain, capable of transmitting signals to other neurons.
The ANN structure for solving the direct problem, in V. S. Abrukov, Amrith Mariappan, Sanal Kumar, Darya Anufrieva, “Comprehensive study of AP particle size and concentration effects on the burning rate of composite AP/HTPB propellants by means of neural networks. Development of the multifactor computational models. Direct tasks and inverse problems & virtual experiments”, Preprint, October 2020. Licensed under an Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0)
For the lines in the network to literally configure physical paths and the points to appear as real destinations, we have to look at a further materialisation of the notion of the network, in which the metaphor becomes space, and space an architectural project. In 1963, the architects Candilis, Josic, Woods and Schiedhelm won the international competition for the new campus of the philological institute in Berlin. Their design had the purpose of transforming the campus in a deeply interconnected “city” endowed with internal streets, squares, courtyards and multiple walkways. The network would appear as a guiding scheme in the project presentation, as it would translate in a spatial grid without any hierarchical distinction between classrooms, departments and facilities. Behind the proposal was a radical rethinking of the educational system: the figure of the network—the ideal of horizontal communication among students and teachers—becoming actual space. In this project, the thinking-devices based on combinatory logic which exteriorise the brain processes would become a full environment where multiple paths allow people to walk across an urban landscape of information and produce new knowledge.
Candilis, Josic, Woods, The Free University of Berlin, Plan of Upper Level, 1963-64