Digital humanists who seek to subject complex realities to computational methods of analysis must first build and manage complex models, conceptualised in terms that embrace but exceed the familiar dimensions of space and time. This challenge has a long history that may be traced back at least to the early 20th century and this paper will survey that tradition for how it may inform contemporary approaches in the digital humanities. At the turn of the twentieth century, scholars from diverse disciplines were concerned with knowledge organization at a global level, aiming to reconcile new insights from evolutionary theory, the emerging disciplines of psychology and physics (with its novel notions of spacetime) and traditional philosophical and humanist epistemology. Three-dimenstional objects and imagistic thinking played a crucial role in the classificatory systems and knowledge modelling developed by Paul Otlet, Patrick Geddes, Wilhelm Ostwald, H.G.Wells and others. Their approach was conceived to allow both automatic information retrieval and analysis, and a synthesising of knowledge that retained its dynamic complexity. Novel techniques of dimension reduction nevertheless challenged the multidimensional habits of humanistic thought - a tension that the mathematician Shiyali Ranganathan, who developed the multidimensional Colon classification, described in 1951: “Thought is multi-dimensional. But we are one-dimensional beings – that is we still prefer all things to be handled to be arranged in one-dimension […] This means that classification is essentially a transformation of a many-dimensional universe into a uni-dimensional, unidirectional one. Machine tools are expected to perform this transformation.” As the computer proved its capacity to analyse large quantities of scientific information and to make complex calculations, there was criticism of the “efficient” approaches developed by the information sciences. Gerard Cordonnier (1944) had already tried to define “intellectual space” and advocated classification as a collection ordered by points of view. Joseph Licklider (1965) would reassert the value of spatial analogies in the face of linear methods, observing the relative absence from the contemporary debate of reflections on concepts such as “information space,” “semantic space” or “the space of knowledge.” Parallel to these (visual) conceptualizations of space in library and information sciences, historians formulated theories of time and periodization (Pot 1951, 1999), distinguishing types of duration (Braudel, see Tomich, 2012). Their aim was to equip their field of conceptual modelling with rigorous defined spatial metaphors of multidimensionality: to imagine what Kubler described as the “shape of time.” It was, in some senses, the conjunction of these aspirations that Ted Nelson had sought to reify in Project Xanadu (1960s to 80s), espousing the use of viewable units of meaning: “vunits” whose contents are linkable and transclusible (showing their contents). By 2007, Nelson would become frustrated that the World Wide Wide had come to imitate “paper under glass” rather than a vision of true hypertexutality. This paper argues that a decade on, as the humanities increasingly embrace semantic web technologies, reflection on past attempts to explore multi-dimensional conceptualization of time and space can significantly inform current aspirations for the inclusive modelling of complexity in humanistic enquiry. References Cordonnier, Gérard (1944) Classification et Classement. Extrait du Bulletin d’Information Scientifique et Technique. Heuvel, Charles van den (2012) Multidimensional Classifications: Past and Future Conceptualizations and Visualizations, Knowledge Organization 39(6), pp. 446-460. Kubler, George (1962), The Shape of Time. Remarks of the History of Things, New Haven and London: Yale University Press Licklider, Joseph C.R. (1965) Libraries of the future. Cambridge: Mass.: The M.I.T. Press. Nelson, Theodor H. 2007/07/11 BACK TO THE FUTURE: Hypertext the Way It Used To Be http://xanadu.com/XanaduSpace/btf.htm. Pot, Johan H.R.van den (1951) De periodisering der geschiedenis: Een overzicht van theorieën. ‘s- Gravenhage: W.P. van Stockum. Pot, Johan H.R. van den (1999) Sinndeutung und Periodisering der Geschichte: eine systematische Übersicht der Theorien und Auffassungen, Leiden: Brill. Ranganathan, Shiyaly R. (1951) Colon Classification and its Approach to Documentation. In: J.H. Shera, and M.E. Egan (eds.), Bibliographic Organization. Papers presented before the Fifteenth Annual Conference of the Graduate Library School July 24-29, 1950 University of Chicago Press. Tomich, Dale W. (2012) “The Order of Historical Time: The Longue Durée and Microhistory”. In The Longue Durée and World-System Analysis. Edited and with an introduction by Richard E. Lee, Albany: State University of New York, 9-34.