Photo-realistic rendering of a room using ray-processing technignes. The second image shows the configuration of the room mo~lel arid scene~. I he hnage was de signed and implemented by Francis Kelly. The project W.LS supe~ised bv Sidney Newton.
Virtual reality is a computer technology that presents sensory infor mation and feedback to give the convincing illusion that the technol ogy user is immersed in an art)ficial world_a world that exists only inside the computer.' The technology is sometimes termed immersion technolo~. It uses specialized computer hardware and software to provide a highly sophisticated level of human/computer interac tion. Virtual reality currently uses special helmets that place binocu lar images before the eyes of the technology user (stereopsis). The helmet also allows the position of the viewer's head to be tracked so that the images of a three-dimensional scene change according to the viewer's movements. Various devices, such as the control stick, three-dimensional mouse, and data glove, permit touching, moving, and feeling "virtual objects." Using this technology, one can "move through" and manipulate a three-dimensional environment, such as a building interior.
The proposed immediate practical applications of the technology are controlling robots located at remote and dangerous sites, con trolling delicate surgery,2 and enabling "walk-throughs" of uncom pleted designs, such as those of buildings3_though virtual reality is also expected to apply to the fine arts, entertainment, education, and communication. Extensives summaries of various applications are provided by Helsel and Roth-t and Hattinger et al.5 Virtual-reality technology is also said to provide the opportunity for new modes of
human-computer interaction, and is considered to provide a new medium for designing in three dimensions.
Ihe study of virtual reality is fascinating because of the practical possibilities it seems to open up but also, as discussed in the previous chapter, because of the claims made about the "new worlds" it may open up to the senses_the electronic worlds of "cyberspace."6 According to Heim, "The final point of a virtual world is to dissolve the constraints of the anchored world so we can lift anchor . . . so we can explore anchorages in ever new places."7 Virtual reality technology is said by some to enable the depiction of "idea space" and the use of "visual metaphors for mental models of how the idea space is organised."8
It is also claimed that the technology is highly sign)ficant in that it will open up challenges to orthodox views of reality. According to Helsel and Roth, virtual reality is a topic "that will raise more (and perhaps more sign)ficant) questions concerning the nature of reality than the human race has faced to date."9 Others add that it challenges our views of our bodies and ourselves. According to Walser, ''fYlour conditioned notion of a unique and immutable body will give way to a far more liberated notion of "body" as quite disposable and, generally, limiting." i_ According to some, we will find that with virtual reality it is possible to change from one body to another, according to what the situation demands. This will have profound effects: ' The ability to radically and compellingly change one's body-image is bound to have a deep psychological effect, calling into question just what you consider yourself to be."~ Virtual reality will also provide safe spaces. Spaces can be constructed in which there are no hazards. According to Heim, "Danger and caution pervade the real (existential) world, but virtual reality can offer total safety, like the law of sanctuary in religious cultures.",2
Notwithstanding these claims, the current commercial manifestations of virtual reality are relatively mundane and include simulators, sucl1 as flight simulators~3 (though not usually exploiting stereopsis), arcade games, and theme park rides. At the time of this writing, virtual-reality researchers consider the technology to be at a ruclimel1tary stage in relation to its potential. The binocular images are jerky, resolution is low, the scenes modeled have to be very simple,
181 Representation and Reality
and there are problems in calibrating the equipment for individual users. The complete immersion environment is not yet with us, in which images are projected directly onto the retina and users wear body-quits of "intelligent sensor effectors" or "data suits."
Studying the claims of virtual-reality technology is valuable, because it brings into sharp relief certain major assumptions that underlie the use of computer technology, particularly in humancomputer interface (MCI) and computer-aided design (CAD) research. Virtual reality takes these assumptions to the extreme, and any testing of them will have implications for other aspects of CAD research. It also provides a good test case for the applicability of contemporary philosophical thinking to CAD. Does what we have outlined so far in this book have anything to say of which HCI, CAD, and virtual- reality researchers should take note? In this chapter, I further apply Heidegger's thinking on the nature of being-in-theworld, and his commentary on what happens when we take technologies to their extremes.
The idea of virtual reality relies on certain assumptions about perception and representation. Only a brief summary of these assumptions will be provided here. Broadly speaking, there appear to be two schools of thought on perception and representation that dominate research into HCI, CAD, and virtual reality. Virtual reality appears to favor one school over the other. Later we will see that both schools are under challenge from Heidegger's concepts of truth.
One view of perception is data oriented. Perception is seen largely as a matter of data input to the mind from the environment. This is considered to be the starting point for a consideratioll of perception. According to Fisher, "We obtain raw, directed information in the process of interacting with the situations we encounter."'"
According to this view, we need more and more input to the senses to effect a sense of the real_"more" in the sense of a greater quantity of data and a greater degree of detail. This assumption is evident in the quest for visual realism in computer-graphics research generally. According to one textbook on computer graphics, in the real
world, "[t]here are many surface textures, subtle color gradations, shadows, reflections, and slight irregularities (scuffs on the floor, chips in the paint, marks on the wall). These all combine in our mind to create a 'real' visual experience."'5 This view also seems to characterize the body as an elaborate input device. According to Rheingold, "our eyes are stereo input devices; our eyeballs and necks are sophisticated, multiple degree-of-freedom gimbals for moving our stereo sensors. We are elements in an information ecology that creates the useful illusion we call 'reality.' ,,\6
It would be rare for this view to be held to the exclusion of other views. The data-oriented view is in tension with the counterview that our perceptions are primarily constructed_the constructivist orientation, according to which we rely on simple cues and clues from the environment. So we can be immersed in any environment, depending on our state of mind, our interests, what we have been taught to experience, our personal and corporate expectations, and our familiarity with the medium. The view suggests that simulators are effective because the users are immersed in their task and in the culture in which the simulation experience makes sense. The same applies to computer games and entertainment. The plausibility of the constructivist view of perception is widely acknowledged but is less privileged as a research drive in virtual reality. The constructivist view suggests that virtual-reality technology does not have to strive for realism through better and more complete sensory input.
The data-oriented and the constructivist views of perception are rarely seen as independent. The notions of environment (the object world) and organism (the subject) are closely coupled in J. J. Gibson's ecological view of perception." According to Gibson, organisms are so enmeshed in their environment that one cannot be understood without the other. Hagen summarizes Gibson's position: "[T]o specify or describe the environment of the organism is to characterize, in general terms, the organism itself; to describe the organism is to outline the general character of its environment."'8
VR seems to favor the opinion that the images generated by the technology and presented to the viewer are general, are invariant, capture the essence of the scene, and are independent of the viewer.
183 Representation and Reality
What is provided by a virtual-reality system is a universal field of sensory input. Viewers may apply their own constructions to this field and thereby engage in some kind of "filtering," though these constructions appear to receive less attention in virtual-reality research_which appears to be driven by the quest for more and better data input to the senses. Ignoring the constructed nature of perception suggests that a virtual-reality system for a frog would be little different from one for a human.
Similar distinctions apply to understanding how representation and the presentation of visual images operate. The correspondence view of representation relies on the idea that a representation corresponds with what is out there in the object. So, according to Hagen, perspective images are realistic because "there is a one-to-one mapping of the visible surfaces of the world onto the picture plane, ancl from there to the eye."'9 The correspondence view also assumes the world contains structures, which we can discern and represent. The privileged view is that geometry and number provide the basic underpinnings of the world. (Some commentators think that whether or not these structures inhere within the world "out there" or in the mental constitution of the observer amounts to the same thing.20) The privileged view assumes that if we can capture the basic geometry of the world in a computer system then the representation of this information is an accurate reconstruction of reality. This appears to be implicit in the just)fication of research into the techniques of fractal geometry, as outlined by Barnsley.
Classical geometry provides a first approximation to the structure of physical objects; it is the language which we use to communicate the designs of technological products, and, very approximately, the forms of natur.ll creations. Fractal geometry is an extension of classical geometry. It ca~ be used to make precise models of physical structures from ferns to galaxies.... Mou can describe the shape of a cloud as precisely as an architec~ can describe a house.2'
A reliance on the geometrical underpinnings of the world is also evident in CAD research, as indicated by Mitchell.
Underlying any design medium is some method of geometrical description_some strategy for using geometrical entities to describe three-dimensional physical artefacts....
ln a CAD system they [the geometrical entities] are represented symbolically within the framework of a Cartesian co-ordinate system, and display hardware is used to translate them into visual equivalents.22
The primacy of geometry is also evident in models of how sense data reaches the eye, as in ray tracing, a technique for generating photorealistic computer images. Some think ray tracing replicates the "real physics"23 of light passing through lenses.
Recalling Scruton's and Mitchell's distinctions presented in chapter 3, the idea of truth in representation is implied when we talk about degrees of correspondence. Some representations seem to be closer to reality than others. This is implicit in the distinctions made among realistic, figurative, and abstract representations. Representations may also be accurate or ambiguous, denoted (actual) or connoted (implied), and they may fall along a continuum, as indicated in Foley and Van Dam's textbook on computer graphics.
At one end of the continuum are examples of what is often called photographic realism (or photorealism). These pictures attempt to synthesize the field of light intensities that would be focussecl on the film plane of a camera aimed at the objects depicted. As we approach the other end of the conthluum, we find images that provide successively fewer of the visual cues.Y~
According to some, the best kind of representation is one that does not need to package and unpackage the information inhere!lt in a scene through the medium of a picture but confronts a duplicate of the real scene. According to Fisher, "A truly informative picture, in addition to merely being an information surrogate, would duplicate the physicality of confronting the real scene that it is meant to represent."25 The correspondence view of representation generates certain research interests, such as developing models (computer algorithms) to produce greater photorealism and developing techniques for storing, processing, and presenting more-detailed data. This involves developing accurate data representations, complete and canonic data structures, and better simulation of perspective, color, texture, edge quality, illumination, light, haze, focus, motion
blur, and movement.26 Virtual reality adds research into other sensory data, such as sound, touch, and movement.27 According to Folev ancl Van Dam, in the case of visual images, the objective is to "produce computer-generated images which are so realistic that the observer believes the image to be that of a real object rather than of a synthetic object existing only in the computer's memory."25 This is a kincl of Turing test for photorealism and virtual reality. The goal appears to be reached when we cannot distinguish between the computer image and the real thing, though this goal is elusive. As with art)ficial intelligence (AI), one may ask what will be the end point of the researcll process? What is the threshold of sophistication atwhichwewill be able to say that a suitably convincing illusion of reality has been achieved? Some major unsolved technical problems include simulating the kinesthetic experience (e.g., walking), allowing the eye to change focus according to distance of object from the viewer, allowing for peripheral vision, and integrating the many theories and techniques that appear to constitute our perception of reality.
Virtual reality is also intriguing because it appears to take the iclea of the underpinnings of number and geometry to a logical extre~ne. If virtual reality works, it vindicates one aspect of Cartesianism_tht reduction of space to number. (This is similar to AI as a test of Cartesian cognitivism.29 If AI works, then it would appear that logic and number underlie all human thought after all.)
The second common view of representation, as for pc rception is constructivist, according to which the appreciation of''realis~ll' lms to be learned. Representation is a cultural phenomenon.~" Hagen summarizes this position: "One learns to read the conventional SNtmbols of a culture's picturesjust as one learns to read the conventio~lal words of a language."3~ According to this view, the langtlage of representatiol1 is in a sense arbitrary. It involves a recognition that iclentifying structure is a human projection, and there may be manN structures. This appears to be a less privileged view in virtual-reality research than the view of representation as correspondellce. Whilc supporting the basic tenor of virtual reality research, Helsel ancl Roth make passing reference to the challenge posed by the constructivist view to the research. It is readily acknowledged that histol~ is always biased according to the historian's viewpoint_so, too, clo
drawings, models, and other artifacts bear the biases of their creators: "How will any individual or group carefully and sensitively, with a deep appreciation for cultural, racial, religious and gender bias, create virtual reality systems?"32
If the constructivist view is followed with conviction, it implies that practice has priority over any thecny of correspondence (a view consistent with Turbayne's elaboration of a linguistic model of vision33). Any drawing or model makes sense by virtue of our immersion in a culture of particular practices, and in the context of our practices.34 There is a way of considering drawings and models such that we need not appeal to the idea of their representing anything. They are a medium of exchange. Shop drawings, working drawings, diagrams, instructions, and schedules have the same "representational status." Each needs to be interpreted in a particular context of practice. This is a familiar idea to computer-graphics, HCI, CAD, and virtual- reality researchers but does not appear to feature prominently in their writing about images. (The discussion within media studies35 appears to be more wide ranging however.)
The idea of practice is partly captured by the idea of language (as long as we do not see language use as following a system of rules). As we have investigated in chapter 1, there is no theory of practice_ hence the priority within theory-oriented academic communities given to the idea of graphical images as corresponding to something and of realism as close and accurate correspondence.
The priority of the practice of reading drawings applies equally to working drawings, three-dimensional computer images, and figure drawing. We learn to "read" drawings. There are different styles of drawing. Our appreciation and understanding of a drawing changes over time, as we become part of the "appreciative community." We tend to privilege "accurate perspective," but perspective drawings are not superior, say, to medieval images, which adopt a different convention, or more realistic. Different conventions are in play, and conventions build on conventions.
Similar arguments can be applied to computer models of designs, such as building designs. The quality and appropriateness of the representation depends on how the computer model is used. There is
l
l
no essential, closely corresponding, canonic description from which all others can be derived.
Applying the constructivist view to virtual-reality systems, we may assume that we learn to use these systems in a context of particular practices. As for the constructivist view of perception, the research quest need not be for realism. The computer can serve as a medium like any other, with its own idiosyncrasies. The idea that computer images may always look like computer images should not deter us, and the virtual-reality experience may be interesting and useful independently of what the experience might or might not correspon<1 to_a view common among those who advocate computer graphics as a medium other than for realism.36
Needless to say, there is a tension between these two views_the appreciation of images through correspondence or through construction. It is not a simple matter to reconcile them, and the former appears to be highly privileged in the way HCI, CAD, and virtualreality research is generally directed. It is in the interstice of such a dilemma that the application of Heidegger's thought proves vahlable yet again.
As we have already seen, Heidegger was very concerned about tecllnology taken to an extreme_for example, what is happening in genetics research, space exploration, and computing.3' We are in a technological age, and, according to Heidegger, technology is llO\V so powerful that we define ourselves and our world in relation to it: "Our whole human existence everywhere sees itself challenged . . . to devote itself to the planning and calculating of everything.... and to carry this manipulation on past all bounds.' 73R Heidegger was, of course, dismissive of computing. In the 1960s, he commented. "Today, the computer calculates thousands of relationships in Ollt second. Despite their technical uses they [the relationships] arc inessential." 39
The constructivist argument given in the case of representatioll can be seen as a rough first approximation to a Heideggerian line of argument. Heidegger gave priority to the habitual and sharecl
practices of making and doing over the specialized practice of theory construction. Theories are esoteric, belonging to the particular practices of scientific and related communities. But, as we have seen, there is a more radical reading of the Heideggerian position. Heidegger was concerned with constructing new understandings of what it is to be in the world, understandings that break down the conventions by which we must decide between (1) truth and realiqy as correspondence and (2) truth and reality as determined by social construct_also seen as a problem of objectivity versus subjectiviqy. He saw the posing of these and other distinctions as an unfortunate legacy of two thousand years of Western philosophical history, a history that culminated with Descartes's definition of the primacy of the divide between the thinking subject and the world of objects.
Heidegger was also strongly influenced by the later writings of the eighteenth-century German poet Holderlin, from whom, to the frustration of the modern reader, he borrowed romantic metaphors, such as earth, sky, gods, and mortals, to elucidate his arguments.
It is worth briefly considering some Heideggerian arguments against the idea of virtual realiqy before considering his views on truth, through which it is possible to marshal some positive suggestions for the direction of virtual- reality research.
First, as explained in chapter 4 in relation to space, Heidegger posited a powerful counterargtlment to Descartes's priority of the subject-object distinction that underlies the oppositions referred to earlier (perception and representation seen as the input of sense data and correspondence, versus social construction). (Heidegger's ideas have been taken up in the context of perception, notably by Merleau-Pongy.4") Whereas Descartes began by asserting that the only thing beyond donht was that he was there doubting (thereby positing the primacy of the subject), Heidegger pointed to our more primordial (basic) experience of being involved, unaware and thoroughly engaged in making and doing, in which there is no subject or object.4' Such clistinctions (subject and object) emerge in the event of some discontintliq~ in our working_a breakdown. They are fluid, contextual, anci clerivative, and they reflect our cultural preoccupations and prejudices. Similarly, the notion of pure sense data
is illusive. No one has experienced it. It is a useful construct of certain kinds of scientific and philosophical investigation.
Heidegger was concerned to reverse the reductive Cartesian ~visdom that an understanding of the world and our place in it can be accomplished by considering simple parts to make a complex whole_number as a basis of understanding space, logic as a basis for understanding thought, sense data as a basis for understanding being in the world. Heidegger would have had little time for a technology that claims to simulate realigy by building up an experience from geometrical coordinates, or that barrages the viewer with sense data and then claims to have said something about realiqy.
Second, Heidegger argued strongly against the notion of "being" as "being made"_what he termed the "productionist metaphysic." That is to use technology as the driving metaphor for how we undeI stand things in nature, as constructed, like technological equipment, though without purpose. Similarly, the productionist metaphysic presents art as something made, like equipment, but with ''vahle added."42 It is likely that Heidegger would have seen the idea of constructing reality (or its resemblance) through data and algorithms as untenable. The idea is the ultimate reduction_the ultimate manifestation of the productionist metaphysic. It is as if to sa_ nature is constructed, so let us reconstruct it in a computer.
Third, according to Heidegger, our primordial understanding of being in the world is one of undifferentiated involvement. Things arc disclosed through breakdown, in a situation. The idea of virtual reality is that everything in the field of view is presented to the senses. Heidegger observed that science operates with this "optic" assumption. It treats things as ever "present-at- hand," laid out for our inspectiotl, and knowable_a useful exercise, within limits.43 Seen in this light, virtual reality is a literal enactment of the Cartesian ontology. It cocoons a person as an isolated subject within a field of sensations. In so doing it attempts to turn being into an ontic phenomenon. The claim is that everything is there, presented to the subject.
Because everything Heidegger suggests about our being indicates that we are not constituted like that (a subject in receipt of sense data), the fully realized virtual-realiqy environment would appear at
best completely unreal, at worse a world without differentiation, pulling us in every direction at once.
Fourth, the dark side of a technology is where it purports to make everything accessible as a potentiality to be exploited.44 Heidegger sees some technologies as enabling, fitting into a new and emerging pattern of human practices, and revealing something about the environment in which they are situated. Recapping Heidegger's example of the bridge_the bridge reveals the banks and the character of the river, through the way it is reflected in the water and the way the pylons have to be built to withstand the river's flow. By way of contrast, a hydroelectric scheme appears to reveal "nothing of sign)ficance" about the river. The river becomes a potential to be exploited as an energy source. According to Heidegger, the hydroelectric technology brings all things to the same level. It tells us that the river is no different from coal dug up from the ground. Clearly there are also inappropriate bridges and appropriate dams (and the example is a romantic one, strongly influenced by Holderlin's hymn to the Rhine), but Heidegger's point is clear. Certain technologies appear to exhibit a leveling characteristic through which whole slabs of the environment, or our experience, are reduced to some common denominator, such as energy, data, or measurement.
We could extract similar examples from the world of computing. A computerized drawing system is enabling in many ways, including in what it reveals about the geometrical and transformational aspects of line, color, and composition in the practice of drawing. The technology makes no claims of completeness. It does not purport to present the last word on drawing, present the complete drawing experience, or reduce drawing to an essential set of geometrical manipulations; neither are these goals necessarily built into the research that surrounds the technology. On the other hand, virtualreality technology seems to be driven by the goal of presenting the last word on reality. Everything will be described and represented. Virtual reality places "reality itself" into the computer. Even other people can be objects in this world. Through this technology, it will be "obvious" that the appropriation of reality is simply a matter of data processing, and, as with the hydroelectric dam, everything be
comes (according to this Heideggerian reading) a potential for exploitation.
Fifth, Heidegger also wrote about the nature of things_ordinary things, like jugs and shoes.45 Needless to say, he did not see things merely as collections of properties. In the light of his sensitive consideration of the nature of materiality and culture (more specifically his complex argument about the collision between "earth" and "world"), it is implausible to imagine that we could model even a mundane thing, such as a jug, in a computer such that the model could manifest anything beyond what it was intended for: that we could warm it with our hands, feel the weight change as we filled it with water and flowers, hold it up to our ear and hear the sea, or watch our distorted reflection in the droplets forming on the outside as we remove it from the refrigerator. These irregularities are not inessential to what it is to manipulate ajug and make the experience.
These arguments suggest thatwe should be cautious in the development of virtual-reality technology, change the way it is talked about, and change the claims that are made of it. However, it is possible to embark on a more positive project from a reading of Heidegger. Bearing in mind these cautions, and an awareness of its limitations, what possible use could there be in virtual- reality technology?
Truth and Representadon.
In Being and Time, Heidegger directly addressed the issue of truth as correspondence.46 His arguments have something to say about the idea of truthful representations, hence indirectly about virtualreality technology's quest for realism. Heidegger did not object to the idea of truth as correspondence but pointed to a more primordial understanding of truth. He asked, how is it that the idea of correspondence is possible in the first place? Before we can make a statement that something corresponds to some state of affairs, there must be a particular comportment or disposition toward the thing or the state of affairs we are talking about. He argued that what enables us to identify a correspondence in the first place is our disposition to be open to the nature of things. In an "authentic" Sittlation, we cultivate the freedom for things to disclose (i.e., reveal)
themselves.4' according to Heidegger, this idea of disclosure was evident in the original meaning of the Greek word for truth (aletheia). Aletheia meant nonconcealment, or disclosure, the idea of truth al but covered up by a subsequent philosophical concern with the notion of correctness, or correspondence. As with many of Heidegger's arguments (about sensation, knowledge, practice, theory, being, and truth), there is an appeal to something more basic or primordial than what is revealed through our modern orthodoxy.45
In the case of truth as disclosure, what is disclosed? Primarily it is a world that is disclosed, well understood in this context as a culture or some aspect of it_perhaps some aspect of human practice. Heidegger illustrates how the work of art discloses a world.49 He describes a pair of peasant shoes depicted in a painting by van Gogh. We find out from the signs of wear and soiling about the life of toil working the land. It is less interesting to remark on whether the picture is a true likeness of something than what the picture discloses or, rather, how truth is at work in the picture. The notion of true likeness is only meaningftll in a specialized realm, as in the practice of constructing or analyzing perspective compositions.
What is the immediate value of this notion of truth (as disclosure) outside of an appreciation of art? We can recall one of Heidegger's famous examples, that of the Greek temple. A modern analysis might be that first there is a context of people, plants, and topography; that these are stable and unchangeable; and that they may have constituted a fitting environment for building a temple.5" The temple was added to this context at a particular moment in time. However, appreciating the disclosive nature of the temple (a consideration of "how truth is at work" in the temple) compels tlS to look at all this in reverse order. According to Heidegger, the temple "discloses a world." It brings the physical envirorlmel1t (earth) into presence (which is simply a stronger way of saying "it reveals something about it") and provides an identity for the people using it, an outlook on themselves (world). How did the temple bring the physical environment into presence? Its solidity reveals the ephemeral nature of the trees and the ocean. It brings them into presence in their many attributes (it reveals their many attributes). The columns catch the sun's rays at dawn and thereby reveal the
nature of the sky. In the case of the temple as an authentic work, as part of the cultural practices of its day, it also brings the deity into presence. Nowadays the Greek temple is a museum piece, in which these aspects of how truth is at work are partially lost or changecl. The world is now that of art connoisseurs, tourism, the culture of romantic painting, academic scholarship, history lessons, nostalgia, and so on. Similarly, a bridge discloses (brings into presence) the banks of the river and the movement of the water itself. It is not that these features are already there and the bridge simply draws attention to them. To assert as much is to make "optic" claims_ to assume that everything is basically there and present (part of the game of science).
What can be said about the disclosive capabilities of working drawings, such as the blueprints of a temple or a bridge? The orthodox account might be that blueprints convey information about objects, materials, sizes, and spatial configurations as instructions from the designer to the builder. What is in the drawings corresponds to how the structtlre is to be manifested. Heidegger does not discuss working drawings, but he writes about assertions (straightforward C0111municative utterances in language),5~ and we can extrapolate a Heideggerian line of argument in which the orthodox view takes second place.
There are constructioll practices_the activities of builders an~l tradespeople, who, left to their own devices, will skillfully build tenlples and bridges (as we see in the exercise of certain craft skills, sucl~ as erecting simple buildings and making simple furniture without working drawings, and some speculative building practice) in keeping with their practices. Drawings are interventions into those practices. Drawings make sense through familiarity with the skilled practices of producing and reading blueprints and of local COIIStr UC - tion. As such, the drawings contain cues or correctives to habitual practice: rather than continue the concrete of the column into the beam, place a steel support between them; rather than extend thc rafters beyond the wall, stop the roof at a parapet. As interventions into construction practice, the drawings reveal aspects of the builcler's own practice to the builder and, hopefully, to the designer. StlCcessful architects seem to be those who have developed this rapport
with local construction practice, and builders have been known to change their practice through working with architects. Seen in this light, the drawings can be said to reveal a changing world of practice. This revealing constitutes a predisposition within which it is possible to adopt the shorthand language of "this line corresponds to a wall" and "locate window A in wall X" According to this Heideggerian understanding of working drawings, unless the drawings first disclose such a world, we cannot see them as corresponding to anything nor as providing sets of instructions.
Similarly, an integrated CAD system and database discloses the multifarious practices of consultants, contractors, and statutory authorities. Otherwise we might be deceived into thinking that the model in the database corresponded primarily to the essence of some built form. Similarly, a photo-realistic computer perspective seems to disclose a world of computer-graphics connoisseurs and marketing practices. What does a virtual-reality system disclose? How is truth at work in the virtual-reality system? In order to address these questions, it is helpful to look more carefully at an aspect of disclosure only hinted at so far. An important aspect of Heidegger's notion of disclosure is the role of difference.
Science and related fields seem to trade heavily in the importance of similarity: this situation is similar to that situation. Science searches for the underlying structures of things and phenomena. It is expected that once we get beneath the surface, we can find out what things have in common and thereby understand them better. Phenomena are abstracted so that they are describable in the same way. The medium of abstraction is commonly that of categories, entities, attributes, and quantification52 or number, formula, logic, and rule. This interest in similarity is evident in the quest for the structures underlying language and social practices (as in structuralism). It is also evident in the concern in design fields, such as architecture, for identifying typologies, generic forms, and ordering principles.
In the field of computer graphics, computer images are often considered interesting because they are similar to photographs. It is also
thought that images are fascinating because they are similar in some way to the real thing. Apparently virtual reality has the attraction of supposedly being so like the real world that we are deceived into thinking we are in the fabricated reality.
In our discussion of deconstruction in chapter 3, we examined Derrida's identification of the role of difference in language. It is not necessary to search far to discover evidence in human thought for the primordiality of difference as opposed to similarity. Saussure53 demonstrated that it is difference that makes language possible_the difference between this word ("cat") and another word ("sat"). Clearly, categorization is not possible without difference. Foucault points to the triumph of difference over attempts to introduce conformity: " [T]he power of normalization . . . individualizes by making it possible to measure gaps, to determine levels, to fix specialities . . . all the shading of individual difference."54 As we have seen, Derrida makes maximum play on the nature of difference, even to the extent of creating a new word (differance) that implies (in relation to language) "that meaning is always deferred, perhaps to the point of an endless supplementarily, by the play of signification."55 To focus on difference is to embark on limitless discovery. By contrast, identifying sameness seems to close off discussion.56 If we are intent on finding Otlt what is the same about things, then our search ends when we achieve the goal. On the other hand, difference reveals further difference. Difference also opens up the possibility of dialectic, the revealing interplay between two entities discussed in chapter 2. (We tend to applaud the discovery of similarity as a basis for bringing people together. In the light of the importance of difference, an "authentic" community is not one in which everyone thinks the same way but one in which the differences are most revealing.)
The theme of difference runs through Heidegger's thinking. Heidegger talks about the disclosive nature of the friction between what he terms "earth" and "world." Traditional discourse on art focused on matter and form: how form was given to materials, how nature relates to culture, how chaos is tamed with order. Generally, it was a case of form being imposed on matter. This inevitably led to tile orthodox dialectic about object and subject. Heidegger recast the
issue through new metaphors, or rather old, primordial metaphors. For Heidegger, the distinction was between earth and world. Rather than chaotic or formless, the earth is that which is not knowable. What it "brings forth" (reveals) it also conceals. Earth offers the greatest resistance to the "openness" (truth) made possible by the work of art. World is well understood in terms of the culture of a people, in the sense of Hegel's idea of an epoch. So, the earth conceals, whereas the world reveals. However, rather than assert that the artwork exposes features hidden in the earth, that is, reveals or imitates nature, Heidegger says that in an artwork or an artifact, " the earth towers up within the work."57 This towering up is in the direction of a world, with which it is in inevitable conflict. Kockelmans describes the phenomenon as follows. "The conflict and strife between world and earth is 'fixed' in the Gestalt [roughly, holistic structure] of the work and shows itself in and through it."58
How can we translate this lofty characterization of the importance of difference into a consideration of HCI, C:AD, and virtual reality? According to Heidegger, a drawing (e.g., by Durer) "draws Otlt the fissure . . . between measure and that which is without measure."59 In any drawing, there is a tension between an ordering scheme and that which defies order. The floor plan of a cathedral embodies a dialectic (the interplay between two entities enabled through difference) between a system of spatial and structtlral organization (world) and the materiality of the site, stone, mortar, timber, and glass (earth). There is a clash between order (a major preoccupatiol1 of the zvorld of the designer) and the realized materiality of the building (eartl1). Seen in this light, icdentifying a grid system (what makes this building similar to that building) in the analysis of a building is relatively trivial. The excitetnent of a builcling lies in the difference betweell systems of order imposed on it (e.g., the imposition of a C.hlisti;lll order Ol1tO an Islamic one in the C.ordoba mosqtle). the destrtlctioll of the grid. and the de\iations from regularit`-. There appe;ll-s to be no theol~- of difference. in the sense of a mathematical or cvn1holic forllltllatioll bv wl1icll we can predict. \~1~at is interestil1g is svhat passes througl1 the gaps. whicl1 is mostl`~ evel~-thillg.
of signs.60 The difference between two marks on the drawing enables us to identify one set of marks as a window and the other as a door. Second, there is the huge gulf between what the drawings are supposed to represent and what is actually realized. This difference is the building realized in materials on the site_the construction process as a kind of dialectic. Third, insofar as they describe anything, what the drawings do not describe are the skills base and experience of the contractor and those in the trades. In this way, the drav~i~,gs reveal the world of construction practice through difference. Fourth, there are the skilled practices of building construction into which the drawings intervene. The builder would do one thing (perhaps build the wall entirely of brick), whereas the drawings are produced in such a way as to ensure that something different is accomplished (perhaps timber panels beneath the windows). The drawings bring the builder's own practices to light. Similar explanations related to the ubiquity of difference could be presented in tht case of integrated CIAD models.
How does difference operate in the case of a computer technolo~like virtual reality? The technology reveals, discloses, and opens up a world, but not primarily in the sense expected by virtual-reality writers. The world is disclosed through difference.
First, virtual reality brings the clash between "earth" and "world'' into sharp relief. Taken as concrete materiality, the "earth" is the very thing virtual reality attempts to capture in its models. It doe.s so with recourse to the "world" of number and geometry.
Second, the expectations of virtual reality differ from their realization as working computer systems. The dialectic this prodtlces COllStitutes the basis of research programs_the world of research pl-actice
Third, virtual reality informs us about reality, primarily thl-ougll the limits of the technology. A virtual-reality model can only ever he a "closed world." It is unlikely to offer security from real threats, such as starvation or electrocution. Virtual-reality real estate is Ul1likely to appreciate like actual real estate. Virtual reality is unlikely to enable the procreation and nurture of human beings. By most accounts, walking through a virtual building is nothing like the expcrience of being in a real building. Taking this point a little furtl1er.
it may transpire that reflection on the difference between virtual reality and reality will engender new support for non-Cartesian notions of space and sensual experience_a non-Cartesian world of intellectual inquiry. In this sense, virtual reality will have informed us about reality.
Fourth, the enabling character of technology may lie precisely in the difference between the virtual-reality experience and the experience of reality. In fact, it is the difference between virtual reality and reality that seems to drive research. Virtual-reality researchers want people to be able to handle radioactive substances with alacrity and without contamination, perform delicate surgery on tiny organs that appear several yards wide, see straight through human flesh as though with X-ray vision, dissolve through walls, jump off buildings, shrink things so that one can look at them as models and then expand them so one can move around inside. Reality does not seem to afford these possibilities. Nor does it allow you to replay what you have just done, store the results on floppy disk, draw in space with a can of "foam," or swim in a pool of psychedelic colors. Some of this thinking about the unreality of virtual reality is expressed by Heim, though he considered this unreality to be optional rather than inevitable: "Something less than real evokes our power of imagination and visualisation."fi'
These reflections on Heidegger's thought about truth have led to a consideration of difference. The idea of truth as correspondence has given way to the more primordial (basic) understanding of truth as disclosure. Seen in this light, virtual reality fails to impress us with its claims to reveal something new about reality in the sense intended by certain virtual-reality writers. Heidegger's view, furthermore, does not support the data-oriented model of perception on which much virtual-reality research seems to be based. Thus, virtual reality fails, too, in its claims of presenting us with correspondences to reality, of which illusion will persuade us.
In the light of this commentary, any picture, and by extension a computer model presented to the senses through virtual-reality
technology, discloses a world. These worlds are the vast, changing, and slippery realms of human practices (and culture). The edifice of correspondence built on the surface of this world (to mix Heidegger's metaphors) could appear almost anywhere. Dressed in headsets and armed with a data glove, I might be impressed with how well the experience corresponds to what I thought it would be like to observe a computer model with headset and dataglove; what it might be like having points, lines, and planes in the shape of a building in Cartesian space moving past my eyes; having a dream; moving through jelly. All of these constitute correspondences in a particular context. Virtual-reality research cannot ignore the substratum of a "disclosed world" revealed through the technology, as though the whole thing were simply a matter of direct mappings between objects, computer models, and something in the mind.
Would virtual-reality technology have been invented had perception and representation not been conceived of primarily in terms of data input and correspondence? Another way of looking at the phenomenon of the invention of the technology is by appreciating the power of metaphor to drive research projects, to be explored more fully in chapter 7. Seen in this light, virtual- reality technology did not need theones of perception or representation to drive it. In the world within which the technology has arisen, there are many privileged metaphors favoring a technological view of experience. Heidegger's characterization of the "productionist metaphysic" (natural entities as built up) is one example. But technologies like virtual reality trade heavily in other technologies, with which they can be seen to relate metaphorically. Aspects of virtual-reality technology are seen as wearing visual earphones ("eyephones"), wearing a space suit, taking drugs, being on a stage, operating puppets. These and other metaphors have extended the concepts of virtual reality and its research programs. Thus, virtual-reality research is entranced by exploring interesting and enabling metaphors.
The other side of metaphor is difference. Virtual-reality research can be enhanced by considering how different it is from the metaphors through which it is conceived. In appreciating that virtual reality is not like operating puppets, we see that we are not constrained (as though by strings), that we can achieve something other than
entertainment, that the puppets can change identity to become the people operating them, and so on. The virtual-reality experience is not like walking through a building, so we can fly through it, pass through walls, and shrink and expand the building around us. A geometrical model is not like the real thing, so we can distort the coordinate grid as we "move" through it and experiment with different geometrical transformations and projections (isometric or axonometric). Recognizing difference within the play of metaphors opens up the possibility of new metaphors. The issue of difference brings us back again to Heidegger's notion of disclosure.
Our discussion of virtual reality brings us to a consideration of metaphor and of difference, which clearly play a role in how we understand information technology. In the next two chapters, I develop the theme of metaphor more fully, initially by reconsidering the relationship between systems theory and information technology research and development.
as the materials from which the jug is made, which bear a dialectical relationship with light and day, and the seasons into which its use is set; and the jug as a sacred vessel, as a part of abiding ritual in a dialectical relationship with our finitude and mortality. This interplay of gathered concerns (however poetically we may wish to describe it) constitutes the world: "This appropriating mirror-play of the simple onefold of earth and sky, divinities and mortals, we call the world." (Ibid., 179) Elsewhere Heidegger describes the revelatory nature of artworks as a clash between "earth" and "world." For an explanation of the disclosive power of art according to Heidegger, see S. L. Bartky, "Heidegger's philosophy of art," British Journal of Aesthetics 9:353-71. These concepts are discussed further in chapter 5.
79. Heidegger, "The thing," 181.
80. See K Wright, "The place of the work of art in the age of technology," Southern Journal of Philosophy 22:565-83. See also R. L. Hall, "Heidegger and the space of art," Journal of Existentialism 8 (29): 91-108; andJ.J. Kockelmans, Heidegger on Art and Art Works.
81. Ibid., 579.
82. Heidegger, Question Concerning Technology, 13.
83. Ibid.
84. Ibid., 16.
85. Ibid., 17.
86. For similar critiques of mass media, see also T. W. Adorno, "How to look at television," Critical Theory: The Essential Readings, 69-83; and Paul Adams, "In TV: On 'nearness,' on Heidegger and on television," RUA/TV?: Heidegger and the Te.levisual, 45-66.
87. Ibid., 49.
88. Ibid., 28.
89. As discussed in chapter 2, Borgman develops the distinction between devices and "focal things" as a way of showing how we can "let be" in the technological age. See A. Borgman, Technology and the Character of Contemporary Life: A Philosophical Inqu~ry.
1. See H. Rheingold, Virtual Reality; and S. Brand, The Med ia Lab: Inventing the Future at MIT.
2. M. Bajura, H. Fuchs, and R. Ohbuchi, "Merging virtual objects with the real world: Seeing ultrasound imagery within the patient," Proc. Computer Graphics (Siggraph '92) 26 (2): 203-10.
3. M. Deering, "High resolution virtual reality," Proc. Computer Graphics (Siggraph '92), 26 (2): 195-202.
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351
Notes to Pages 179-185
4. S. K Helsel and J. P. Roth, eds., Virtual Reality: Theory, Practice and Promise.
5. G. Hattinger, M. Russel, C. Schopf, and P. Weibel, eds., ArsElectronica 1990, vol 2, Virtuelle Welten.
6. W. Gibson, Neuromancer.
7. M. Heim, "The metaphysics of virtual reality," Virtual Reality: Theory, Practice an~
8. M. B. Spring, "Informating with virtual reality," Virtual Reality: Theory, Practic' and Promise, 13.
9. See Helsel and Roth, Virtual Reality: Theory, Practice and Promise, vii.
10. Walser, quoted by Rheingold, Virtual Reality, 191.
11. Walser, quoted by Rheingold, ibid., 191.
12. See Heim, "The metaphysics of virtual reality," 33.
13. R. Reisman, "A brief introduction to the art of flight simulation," Ars Electronica 1990, vol. 2, Virtuelle Welten, 159-69.
14. S. S. Fisher, "Virtual environments: Personal simulations and telepresence," Virtual Reality: Theory, Practice and Promise, 102.
15. J. D. Foley and A. Van Dam, Fundamentals of Interactive Computer Graphics, 560.
16. H. Rheingold, Virtual Reality, 63.
17. See J.J. Gibson, The Perception of the Visual World; and T. 1 ~.ih~c,,' 7'h~ F,nl,,~,-.a Approach to Visual Perception.
18. M. A. Hagen, Vaneties of Realism: Geometries of Representational Art, 6.
19. See Hagen, Varieties of Realism, 87.
20. See C. Norris, Deconstruction: Theory and Practice.
21. M. Barnsley, Fractals Everywhere, 1.
22. W.J. Mitchell, "Computer-aided design media: A comparative analysis," C.ornpu ers in Architecture: Tools for Design, 53.
23.- A. S. Glassner, ea., An Introduction to Ray Tracing, x.
24. J. D. Foley, A. Van Dam, S. K Feiner, and J. F. Hughes, Fundamentals of Intcrac~i',, Computer Graphic.s, 605. This discussion recalls our investigation of photographic real ism m chapter 3.
25. S. S. Fisher, "Virtual environments," 101.
352
Notes to Pages 185-190
26. See S. Upstill, The RendermanTU Companion: A Programmer's Guide to Realistic Computer Graphics; T. Saito and T. Takahashi, "Comprehensible rendering of threedimensional shapes," Proc. Computer Graphics (Siggraph '90) 24 (4): 197-206; and D. R. Baum, S. Mann, K P. Smith, and J. M. Winget, "Making radiosity usable: Automatic preprocessing and meshing techniques for the generation of accurate radiosity solutions," Proc. Computer C'raphics (Siggraph '91), 25 (4): 51-60.
27. See S. J. Teller and C. H. Sequin, "Visibility preprocessing for interactive walkthroughs," Proc. Computer Graphics (Siggraph '91) 25 (4): 61-69; and M. Deering, "High resolution virtual reality," Proc. Computer Graphics (Siggraph '92) 26 (2): 195202.
28. See Foley and Van Dam, Fundamentals of Interactive Computer Graphics, 539.
29. See H. L. Dreyfus, Being-in-the-World: A C.ommentary on Heidegger's "Being and Time,"Divisonl, 119.
30. N. Goodman, Languages of Art.
31. See Hagen, Varieties of Realism, 86.
32. See Helsel and Roth, Virtual Reality, ix.
33. C. M. Turbayne, The Myth of Metaphor.
34. This view was elaborated on in chapter 3 in relation to photographic images.
35. B. Jones, "Computer imagery: Imitation and representation of realities," Leo nardo, 31-38.
36. See M. Weiser, "The computer for the twenty-first century," Scientitc American 265 (3): 66-75; K. Carter, "Computer-aided design: Back to the drawing board"; P. Haeberli, "Paint by numbers: Abstract image representations," Proc. Computer Graphics (Siggraph '90) 24 (4): 207-14; and S. Schofield, "A general approach to interpretive (non-photorealistic) rendering."
37. SeeJ.J. Kockelmans, Heidegger on Art and Art Works, M. E. Zimmerman, Heide.gger's Confrontation with Modernity: Technology, Politics, Art; and H. L. Dreyfus and H. Hall, Heidegger: A Cntical Reader.
38. M. Heidegger, Identity and Difference, 34-35.
39. Ibid., 41.
40. M. Merleau-Ponty, Phenomenology of Perception.
41. See Dreyfus, Bein.g-in-the-World, 124.
42. See Kockelmans, Heidegger on Art and Art Works, 136.
43. R. Brandom, "Heidegger's categories in Being and Time," Heidegger: A Cntical Re.ader, 61.
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44. See M. Heidegger, The Question concerning Technology and Other Essays; D. Veselv, "The nature of creativity in the age of production," Scroope C.ambudge Architecture Journal (4): 25-30; and D. Vesely, "The question of technology."
45. M. Heidegger, "The thing," Poetry, Language, Thought, 165-86.
46. M. Heidegger, Being and Time.
47. See Kockelmans, Heidegger on Art and Art Works, 157-58; and J. Haugeland, "Dasein's disclosedness," Heidegger: A Critical Reader, 27.
48. J. P. Fell, "The familiar and the strange: On the limits of praxis in the earlier Heidegger," Heide.gger: A Critical Reader, 65.
49. M. Heidegger, "The origin of the work of art," Poetry, Language, 7'hought, 1/87.
50. See Kockelmans, Heidegger on Art and Art Works, 143.
51. Brandom, "Heidegger's categories," 57.
53. F. de Saussure, Course in General Linguistics.
55. See Norris, Deconstruction: Theory and Practice, 32.
56. A. B. Snodgrass, "Asian studies and the fusion of horizons," Proc. Gadamer, Artiou and Reason, 35-42.
57. See Kockelmans, Heide.gger on Art and Art Works, 184.
58. Ibid., 184.
59. Ibid., 185.
60. See Saussure, Course in General l.inguistics.
61. See Heim, "The metaphysics of virtual reality," 30.
1. See for example C. Shannon, and W. Weaver, The Mathematical Theory of C.ommuni cation. For introductions to systems theory, sc e C. West Churchman, The Systems A/~proach; and Nic J. T. A. Kramer and Jacob cle Smit, Systems Thinking.
2. L. VOII Bertalanffy, "General system theory," Ceneral Systems, Ye.arbook of the sorietN for the Advancen~ent of Ceneral System Theory, vol. 1, 2.
3. Kramer and Smit, Systems Thinkin$ 66.