The engineer and educator Peter McCleary, in an essay that leans heavily – as most things do in the philosophy of technology – on the writings of Martin Heidegger, asks a curious but interesting question:
“What are the characteristics of knowledge derived during the production of the built environment?” .
McCleary claims that by picking up a tool and acting on the world we are not only achieving effects – getting things done – but also, and more importantly, learning something new. Like a space-probe prodding the surface of an unknown planet or a blind person navigating a street with the aid of a stick, by extending ourselves outwards into the environment we are also drawing information in, all the time building up a richer picture of what’s going on at the mutable interface of body and world.
The tools that Heidegger labelled ‘ready-to-hand’  are those that can most easily be incorporated – quite literally – into an extended body-image, stretching our sensory surfaces into prosthetically expanded selves . As well as gaining knowledge of the tool itself, in a way that we would never do if we simply stared at it, by putting the tool to work we also learn about our own bodily capacities. More importantly, as McCleary argues, we also learn something about the world THROUGH these bodily extensions, hence they become ‘transparent’ to us in that – with sufficient practice – we almost forget that we are wielding them. By contrast McCleary claims that many of today’s high-tech tools have become ‘opaque’ and inscrutable devices. By removing or automating processes traditionally carried out by hand, these ‘black-box’ technologies deny this kind of direct bodily engagement, often reducing it to the reading of dials and pushing of buttons. His examples include the use of power tools like band-saws and sit-on lawnmowers which while amplifying efficiency also reduce the kind of direct tactile feedback and learning about the materials being worked on which is the by-product of physical effort.
The idea that we experience the qualities of materials through their physical resistance to transformation was usefully explored by the American philosopher John Dewey in his book Art as Experience . He described how we can only become aware of ourselves and our abilities by reaching out and interacting with the world around us, and that the character of what we encounter depends on the degree to which it pushes back. This notion of physical resistance as a key element of a material’s tectonic identity could also be expanded to help understand how we engage with whole building elements and spaces. Here a paradox appears in relation to our usual assumptions about successful functional arrangements: if we only become consciously aware of our tools when they fail to perform as expected, is it also the case that we only really notice our surroundings when they frustrate our attempts to inhabit them? Heidegger captures this experience nicely in describing the moment a tool breaks down in the process of using it, when it suddenly ‘shows up’ again in our conscious awareness as it shifts from ‘ready’ to ‘present-at-hand’. In McCleary’s terms this could also be described as a shift from transparent to opaque, as we go from experiencing world at the ‘cutting edge’ of the tool to simply experiencing the tool itself as a ‘useless’ object.
One conclusion to be drawn from this is that a seamlessly functioning ‘transparent’ architecture would actually result in a ‘building without qualities’. By contrast, it is interesting to recall attempts by architects to find a balance between transparency and opacity by deliberately disrupting conventional patterns of use – as with Peter Eisenman’s famously divided double-bed in House VI which he described as “…extending the possibilities of occupiable form.” . If it is true that learning takes place only as we push against the boundaries of familiarity, perhaps it is useful to rephrase McCleary’s opening question in relation to environments that stimulate and provoke. It may now be more useful to ask: what kind of knowledge is produced in the occupation of the built environment..?
 P. McCleary, “Some Characteristics of a New Concept of Technology”, Journal of Architectural Education, Fall 1988, Reprinted in W. Braham & J. Hale (eds) Rethinking Technology: A Reader in Architectural Theory, Abingdon: Routledge, 2005, pp. 325-36.
 M. Heidegger, Being and Time, trans. J. Macquarrie & E. Robinson, New York: Harper Collins, 1962, pp. 98-107.
 For some recent experimental evidence of this phenomenon see: S. Yamamoto & S. Kitazawa, “Sensation at the Tips of Invisible Tools”, Nature Neuroscience, 04 September 2001, pp. 979-80. I am grateful to Peter Stockwell for pointing out this connection.
 J. Dewey, Art as Experience, New York: Perigee Books, 1980, , pp. 59-60.
 P. Eisenman, House of Cards, New York: Oxford University Press, 1987, p. 169. See also the analysis by Andrew Benjamin: “Eisenman and the Housing of Tradition” in Architectural Design, 1-2, 1989.