Heidegger wants to get at the being of beings. But his methodological access to this (at least at this initial stage of his investigation) is via the human understanding of artifacts. So the question, what is a hammer? becomes, for instance, the question, what is a hammer for a person? —say for the person who is using it to nail something together. Heidegger looks at the tacit sense that we have of a hammer when we are using it. He points out that when we are hammering we are focused on the nail or on the pieces of wood that we are joining or on the project we are building, and not directly on the hammer itself. There is only what Polanyi calls a subsidiary awareness of the hammer as part of the background of the activity that we are focused on. In fact, for the act of hammering to take place effectively, we must be unaware of the hammer; we must be primarily concerned with the task we are pursuing, not with the tool we are using to pursue it. This is part of what is meant by saying that our understanding of the hammer is necessarily tacit: that its use requires that we not focus our attention on it.

When we are engaged in hammering, the hammer is not there in the sense of an object that we relate to as a subject—a subject who might, for instance, formulate propositions about the hammer, like: I am lifting the hammer; the hammer is heavy; the hammer is made of metal and wood. The hammer is only there as part of what Heidegger calls the “totality of equipment” that is available to us and that we make use of in our work. When we are at work hammering, we are in a situation where the hammer, nails, wood, and other tools are available for our use. The hammer is available in order to drive nails, and the other tools are similarly related to their uses. All these references (e.g., hammer to nails for driving them) form a totality of significance, that is definitive of our situation. So the hammer is accessible to us in terms of this system of references among the tools we use. The references inter-relate the tools in terms of their possible utilities, and also refer to people as those for whom the uses are ultimately intended.

Figure 4-3 is meant to illustrate that the hammer is tacitly understood in terms of its relations to other artifacts, concerns, and people. The totality of these things as understood in this interrelated way is the situation. To say that interpretation is situated is to say that everything is interpreted as part of this understood totality, as having these relations.[1]

The entities presented in this figure are involved in many different kinds of relations. For the sake of simplicity, the various kinds of relations have not been identified here.

Heidegger stresses that our understanding of the situation, defined as the totality of references, is necessarily prior to our understanding of the individual tools. We are only aware of the hammer as part of the available situation that defines it via the references to something for driving nails, etc. In this way, we can understand the hammer tacitly only because we always already understand our situation as a significant totality.

Our tacit situated understanding provides a space (a stage or “clearing”) within which elements can be discovered and brought to a more explicit form of knowledge. This process is a central concern because it involves the bridging of tacit understanding (the normal mode for people) and explicit knowledge (required for computer representations). Within the space of understanding given by our being tacitly situated, we can discover new things and understand them in relation to what we already understood. In some cases, this subsumption of new understanding involves us in making our understanding explicit by formulating it linguistically. In this way, explicit knowledge may emerge from tacit understanding when we are situated. However, we can never make all our tacit background understanding explicit.[2]

Heidegger’s difference from all objectivistic philosophies is already clear here. The world does not consist of a fixed set of multiple objects that we can come to know by staring at them and explicitly noting their attributes. Rather, to be human means to have disclosed (opened up) a situation or world within which and in terms of which things can be discovered as already significant. The issue of intentionality, epistemology, or mind/body (that poses the question of how mental activity can gain access to physical reality) is a non-problem for Heidegger because we are already understandingly involved with things when we first discover them (see Heidegger, 1975, and Dreyfus, 1991).

According to Heidegger (1927), our tacit understanding of things is founded upon our situatedness. Understanding can then become more or less explicit on the basis of this tacit understanding:

Involvement in the immediate work-world has a function of discovering such that the beings brought along with the work (i.e., in the references that are constitutive for it) remain discovered in various degrees of explicitness and to various extents of insight, depending upon our mode of involvement in the work. (S.71)

This explains why we understand best when we are properly situated in the context of an issue we are trying to understand. That is when we have access to the associations that are related to the topic of our concern and that define its meaningfulness. It is our involvement with the topic that makes manifest the things, issues, and concerns that are related to it and whose mutual associations constitute our situation.

In Heidegger’s philosophy, to say that we are situated means that we are involved with things in the world and can discover things based on our tacit understanding of what we are involved with. The situation is neither a set of physical circumstances in the objective world nor a model representing such objects in a subjective mind. Heidegger overcomes the separation of world and mind by focusing on the situation as the understood world itself in which we are involved, not a re-presentation of it “in the head.” Of course, we can subsequently represent the structure of the situation in explicit terms: words, graphics, computer symbols. But in our tacit involvement things are there as meaningfully related to our concerns; they are available to us in ways that are not mediated by symbols or re-presentations.

The next question is, then, how our understanding can become more explicit. This is important for Heidegger from a methodological perspective. In order to answer the question of being, he needs to take our tacit understanding of being and make it explicit. To show that it is possible to bring to light the structures that ordinarily operate tacitly, Heidegger gives three examples of cases where an artifact like a hammer stops functioning invisibly in the background and becomes explicitly manifest. These cases are when a hammer is conspicuous, obtrusive, or obstinate. For instance, (i) if a hammer that one wants to use to drive a nail is encountered as unusable, damaged, or unsuitable (too large, broken, or the wrong style) then one discovers its usability for hammering in a conspicuous way. Similarly, (ii) if a tool that one reaches for turns out to be missing, then one becomes conspicuously aware of it as necessary but unavailable. Finally, (iii) if something is in the way of what one wants to do, then that thing is discovered as obstinate. When one discovers the hammer under such circumstances, it is not discovered as a raw physical object, but as an unsuitable driver of nails (or whatever) and the situation in which one is desirous of driving the nail—the related and referenced other tools and human purposes—also rises to a more explicit presence. The situation comes to light as a network of artifacts; it is disclosed as a context of significance that is then seen as having already been familiar as the basis of the tool and its references.

This is a very different view from the usual cognitive science approach in terms of explicit goals, according to which a carpenter who has the goal of producing an artifact formulates propositional sub-goals like joining two pieces of wood, and sub-sub-goals such as lifting the (explicitly considered) hammer and swinging it at the nail with adequate force. In the Heideggerian view, the tool and the goals are only tacitly available by implication or reference as long as everything is going smoothly. It is when the references are disturbed that they become visible. When some tool is missing whose ordinary availability was so obvious that we never even took any notice of it, then this absence creates a break in the totality of references. Our awareness runs into unexpected emptiness, and discovers for the first time the (now broken) references connecting the anticipated tool with the other tools and goals of the situation. Whereas the rationalist tradition tends to think of the being of things as a simple form of physical presence, Heidegger has a more complex view of things being ordinarily hidden in various ways, having to be uncovered and disclosed, only to then re-submerge into tacit, subsidiary awareness. In the hammer example, the hammer itself is hidden when it is normally available, useful, or in use; it becomes explicitly visible to us precisely when it is physically absent or otherwise unavailable.

It should be noted that Heidegger has not claimed that things only become explicitly manifest when there is a breakdown of normal activities. This is a suggestive claim offered by Dreyfus (1991), Schön (1983), and others influenced by them—but it is a stronger claim or a narrower theory than Heidegger’s. Also, it is open to misinterpretation of what the phenomenon of breakdown is all about. One could, for instance think that a breakdown in design is when a designer gets stuck in the flow of designing activity and has to stop to think of a solution. In fact, Schön’s concept of reflection-in-action might suggest this idea, even though Schön himself knows better. This is a point where it is important to understand what Heidegger is up to methodologically in order to understand what his analysis is about. The three examples he gave are just sample cases and by no means rule out other paths to making things explicit. When Heidegger presents them, he is making a methodological point presenting phenomenological evidence for the structure of the situation as prior to the artifacts understood by it. Here he is not proposing a general theory of explicit knowledge or reflection. Even later, when he does discuss explication, he develops his analysis only to the extent needed to make his points about the possibility of explicating the vague sense of the meaning of being. The breakdown examples make manifest the structure of the situation—that is why Heidegger refers to them. What is important is not that tacit involvement in the world is broken, but that the structure of the situation is broken. That is, the network of references is suddenly inadequate for making sense of the world because the references anticipated one thing and something else was discovered in the world: i.e., the hammer was unusable, missing, or in the way.[3]

The important phenomenon is not a matter of psychological consciousness: that one suddenly has to become more conscious about what one is engaged in. Rather, one has to reinterpret in the sense of reorganizing the network of references that define the situation so that circumstances that have been discovered make sense in the revised situation. Heidegger is interested in this phenomenon from an ontological, rather than psychological perspective. The discovered artifact that causes the breakdown loses its ontological status as available to the person’s tacit understanding because that status was conditional upon the situation. Heidegger’s ontological analysis need not be pursued here. The important point for computer support is that a breakdown is a rupture of the situation as the network of references for understanding, and not simply a difficulty in action involving some artifact.

In the cases of designing discussed in the previous chapters—the library footprint and the lunar habitat layout, for instance—tacit situated understanding played a crucial role. The situation for Clara, the architect in Schön’s study (Section 2.3 above), is the library as she understands it. This situation is disclosed to her through her study of the line drawing, which she interprets as a library footprint. Within this situated understanding, Clara can discover things: like the anomalous walls or five foot displacement. Things discovered in the situation are discovered as already having some meaning (a jog in the wall, a deviation from uniformity of lengths, a long way for a library user to walk, a dimension with a certain architectural sense) by virtue of their relations in the situation. When Clara notices the displacement, she is already situated in a world that is meaningful for her. The displacement is noteworthy in terms of its relations to the other walls, to the areas that are defined within the library (especially those affected by the five foot irregularity), to the surrounding lawns or streets, and to the approaches that a visitor could take to the library. It is only within this network of significance that the displacement can be discovered as an object of interest. Perhaps the other architects in the experiment saw the library plan as a different complex of relationships in which the displacement could not be discovered as a significant feature.

One can, of course, ask how Clara’s understanding of the drawing originally gained the significance that it had for her. Heidegger’s point is that one does not first “decide” to understand something—as though one had to label objects with values through rational judgments—but always first discovers things within contexts that are already meaningful (i.e., already related within the situation). In some cases, the discovered meaning can be modified through reflection and judgment, but this is not as common as rationalist theories assume and it is always done on the basis of prior situated understanding. This takes place through the explication process called interpretation (see Section 4.3, below). When, for instance, Clara is first shown the line drawing and told that she is to design a library using the drawing as a footprint, she discovers the drawing within the larger context of her professional life. She already understands what it means to be an architect, to design a building, to visit a library, to participate in an experiment, to study a floor plan, to sketch alternative approaches. She dwells in a world in which the drawing and its associated task are already meaningful, in which significant relationships can be explored, and in which discoveries can be made, understood, and further interpreted.

Ultimately, the various kinds of spatial and functional relationships of the situation point to people: the future library staff who manage the entrances and exits, the stacks, and the offices; the potential library users who walk in from the street, orient themselves after entering a door, search for books or magazines, and use the other facilities. Clara understands these relationships because she has a tacit understanding of the meaning of human being: of what it means to be a person working in the library, a person using the library, a person appreciating cultural artifacts, a person negotiating pathways among physical walls.

The situation as meaningful network of physical, functional, and human relationships plays a central role in Alexander and Rittel’s theories as well as in Schön’s analysis of the library experiment. Alexander is particularly concerned with finding the best decompositions of such relationships in a design, so that the definition of components in terms of their most important or tightest network of interconnections is not disturbed when design decisions are made that rearrange less tightly bound components. Alexander’s analysis of unselfconscious design reveals a strong sympathy for the rootedness of artifacts in the worlds of their creators. Artifacts like native houses serve obvious needs in the physical environments and daily lives of their inhabitants, and their designs function centrally in the local cultures and traditions as well. All aspects of their design are immediately meaningful in terms of the understood world. For Alexander, to decompose a design problem in a way that ignores the ties of structural form to social “fit” is to destroy the integrity and value of the artifact being designed.

Rittel also takes a relational view of design, but he focuses more on the level of rationale for self-conscious design. To argue that design is a deliberative process is to say that a given claim does not stand on its own self evidence, but that it is tossed upon a sea of conflicting opinions. The value of an item of rationale results from the way it swims among the other items and how it survives the buffeting by criticism and argumentation. Ultimately, the significance of design justifications are relative to other design decisions, individual modes of reasoning, and personal or group interests or predilections That is, they are always already primarily understood within a broader perspective of understanding, on the basis of which opinions may occasionally be swayed subsequently. The Rittelian issue-base representation captures the structure of the situation’s inter-relatedness as explicitly as Alexander’s decomposition patterns or Schön’s library experiment.

The role of the situation is perhaps clearest of all in the example of lunar habitat design. Here, two concerns dominate most of the discussion in the videotapes: adjacencies and functional relationships. At the level of analysis reported in the transcripts of Chapter 3, the designers are working with a set of components (sleep compartments, galley, toilet, table, stowage, etc.) that are fairly well determined by general mission requirements. Their efforts are aimed at arranging these component volumes so that their mutual relationships define a meaningful situation for life and work on the moon. So the designers—who understand things from within their situation—are trying to design a different situation that will serve as a world for the astronauts.

It defines both the lunar habitat design situation that is being designed and the situation of the designers designing it.

The designers’ world includes their sense of what it is to be human in a variety of situations, as well as their knowledge of technical information and regulations. They understand, for instance, what it is to get out of bed in the morning, to sit down with other people at breakfast, to yearn for privacy. As designers, they are experienced at using this tacit understanding to project themselves into the situations they are designing and to understand what it would be like to understand things from within that situation. They know (whether or not they articulate it) that this kind of design hinges on the establishment of a coherent network of significance that can support a meaningful life for people in the situation. They structure and rearrange the physical, functional, and interpersonal relationships of the habitat until they have established a nexus in which dimensions of life like privacy and sociability are defined.

The designers project themselves into the world disclosed by these relationships in order to discover the meaning of things for astronauts in that situation. If they discover something that does not work properly, they try to redesign the relationships. When they finally feel comfortable in their new world, then they have reached a satisfactory resolution of the manifold design constraints and they can move on to another level of design. At the conclusion of the design session transcribed in Chapter 3, the designers felt a sense of resolution. They had reached a plateau in their interpretive process at which all the major things they discovered fit comfortably into the network of relationships of the evolved state of their tacitly understood situation.

The lunar habitat design session provides a particularly clear example of how the situation, that is always already understood in a tacit way, provides the working basis for discovering meaningful things within its context—whether one looks at the situation of the designers or at the design of the situation. The lunar habitat design is understood by the designers as a situation incorporating multiple functional relationships. It is designed to be a situation that will be understood by astronauts living in it. But as it exists on a piece of paper or represented in a computer memory as data for a CAD program, it is not understood; it is not a situation; it is not meaningful. Only people can understand.

When NASA compiled the chart of functional relationships and relative adjacencies shown in Figure 3-5 (Section 3.2 above), it may have looked like they recognized the role of architecture to structure human situations. But actually that chart analyses the habitat components as physical objects with functional characteristics that imply certain adjacency constraints. It analyses the habitat as a physical environment that has to function efficiently, without ever explicitly taking into account the fact that most of the functions have to do with people pursuing human aims. The chart of functional relationships does not directly represent the experiential relationships of a situation, but rather incorporates formal, explicit relationships of adjacencies and functional inter-dependencies. However, the chart is similar to an analysis of the designed lunar habitat situation because the formal interpretation necessarily grows out of tacitly understood experiences.

The underlying situation is not to be taken as a physical environment of spatially juxtaposed objects, but as a network of relationships that characterize how one thing is understood as useful to another, ultimately in terms of human purposes. As the basis for tacit understanding, the situation serves as a precondition for understanding from various viewpoints (see Section 4.2) and for more explicit understandings (see Section 4.3).

[1] Recently, in his book rejecting functionalism, Putnam (1988) expressed this idea in the following way: “If I say, ‘Hawks fly,’ I do not intend my hearer to deduce that a hawk with a broken wing could fly. What we expect depends on the whole network of beliefs” (p.9).

[2] As Polanyi (1958) put it, “Tacit knowledge is more fundamental than explicit knowledge: we can know more than we can tell and we can tell nothing without relying on our awareness of things we may not be able to tell” (p. x).

[3] Heidegger’s example of hammering is often cited. However, it is in some ways too pat and raises a difficult question concerning its generalizability. For instance, it conjures up visions of the craftsman’s workshop where, as in an obsolete blacksmith’s shop, one automatically reaches out for hand tools that extend the limbs of one's body. This is an enticing image, given Heidegger’s argument. But one must ask—as do Adorno (1964), Stahl (1975b), Habermas (1985), Lefebvre (1991), Bourdieu (1991) and others—if this is not a romantic vision longing for a return to pre-industrial forms of labor. Is Heidegger insightfully characterizing a primordial foundation of human existence throughout history or is a different analysis of our being-in-the-world needed in an industrial or computerized age? In particular, are Heidegger’s analyses relevant to contemporary design of high-tech artifacts, with or without computer support? Is the individual craftsman the appropriate paradigm for analyzing collaborative design in the contemporary world?

Two general arguments in support of using Heidegger’s approach suggest themselves. The first is the argument from evolution: that advanced forms are built on earlier stages. Donald (1991) and Polanyi (1953) argue that primate-level episodic (tacit) understanding still provides the necessary basis for human consciousness and theoretical knowledge. The second argument is that the medieval workshop is not an anachronism, but still provides the preferable model of organization of learning and work, at least for certain fields. Budde and Züllighoven (1990), for instance, claim that the tool/workshop structure is superior to the CASE/industrial model for software development, and they therefore apply Heidegger’s categories in their hermeneutically-based concepts of software tools for programming workshops. Similarly, Schön (1985) argues that the apprenticeship model of the design studio is more important than the engineering ideal of theory application for the teaching of architecture. Because Heidegger’s examples are suspect, it is important to turn now to concrete examples of interest. In Part II Heidegger’s analysis will be extended to collaborative design to overcome the danger of an ahistorical, asocial interpretation.

4.1. Definition of the Situation as Basis for Tacit Understanding