1 Transcendent and immanent aspects must be interwoven

Either software developers lament "If only software engineering could be more like X..." where X is any intensive-design profession says Dough Lea or experts in computer science spend lots of time discussing the pros and cons of different paradigms in computer science. They pay little attention to the intrinsic nature of the problem to be solved and even less to the global problems mankind has to face urgently.

Thus I introduce a problem and its intrinsic nature straightforwardly: the need to generate architectural/structural/landscape design within an urban ecosystem context enabling the design and planning of sustainable cities. There are fundamental processes underlying what I would call an ecodesign modeling.  Basically what happens in a natural ecosystem also reflects in the urban ecosystem because we are embedded in the former. The green designer's goal is to create an environment to improve the physical, mental, psychical health of the human beings.  Scientists have been showing certain environments help man to keep his cellular oscillations.  R.S. Ulrich compared data of recovery for pairs of patients submitted to surgery who are expected to experience considerable stress. To carry out the experiment, pairs of patients with the same surgery, sex, weight, age, tobacco use and previous hospitalization were booked in identic rooms with exception of the view through the window. A member of each pair looked into a grove, while the other looked to a wall of brown bricks.  Individuals with view for trees needed only aspirins, recovered sooner and left the hospital earlier. The wall patients received more analgesics, narcotics, complained quite a lot and spent more days at the hospital.

I am going to trace back the implicit origins of the latter behaviour. In archaic Greece, the notion nomos-physis (law-nature) formed a unity. In the feelings of the ancient Greeks, nomos is primarily the distributive justice from which nobody could escape. Each one had access to a site during his/her existence without the need for written laws. With the advent of currency and the shift from oral communication to writing, a new political space and time emerged accompanied with the dissolution of the basileus - central figure of the archaic communitariam power. The logic of polis prevailed and hence the dissociation from cosmos.

This opened the gate to the Platonic conception of cosmos creation by a Demiurge whose creation is anthropoi, human and male, making us view earth as a passive container or receptacle.The separation fro physis and the cosmos as well as the women segregation has led to an entropic behaviour towards the site and the planet.

Although this has been the mainstream trend, Aristotle's ideas have loomed on the horizon tuning with the scientific ideas of self-organization and pointing forward the environmental degradation even at Greek times. For him, physical research must deal with conditions and characteristics of physical objects without contrasting them with the properties of things eternal. This caused departmentalization but is more than a method. It carries with it a certain autonomy for the subject thus treated.

Summarizing, while Plato cares for transcendent reasons, Aristotle cares for immanent reasons. Our mandatory task is to reconcile both trends in the sense that time is ripe for attempting to incorporate at least embryonically both transcendent and immanent aspects into our approaches.

2 Homeostasis is common to the planet and to the human being

The question is how to introject such an encompassing vision into an ecodesign modeling? First we have to try to discern the fundamental dimensions embedded in the modeling.

James Lovelock in his theory of Gaia unravels the Earth's nature: ...the Earth's living matter, air, oceans and land surface form a complex system which can be seen as a single organism and which has the capacity to keep our planet a fit place to life. Gaia is a cybernetic or feedback system which seeks an optimal physical and chemical environment for life on this planet [Joer92].

Likewise the ergonomist or the human factor engineer is well aware that the general thermal state of the body both in comfort and in heat or cold stress is dependent on an analysis of the heat balance for the human body:

Moreover the triad of temperature, potential evapotranspiration ratio and average total annual precipitation in mm determines a range of natural life zones or ecosystems in terms of world plant formations and their associated local biodiversity.

There are two fundamental processes associated to life: one "order from order"and the other "order from disorder". Hence information and energy are the two ingredients of life. Order from order is the information stored in the DNA molecule and responsible for the generation of myriad of life forms. Paradoxically, the more we try to keep order, the more energy is necessary and the more stress (entropy) is thrown into the environment, because all energy transformations from one form into the other entail waste heat production due to the second law of thermodynamics.

However the recently discovered fourth law of thermodynamics states: If a system has a through-flow of exergy (it is a measure of the potential of energy to perform useful work), it will attempt to utilize the flow to increase its exergy, i.e., to move farther away from thermodynamic equilibrium; if more combinations and processes are offered to utilize the exergy flow, the organization that is able to give the system the highest exergy under the prevailing conditions and perturbations will be selected [Joer92].

I want to convey the idea the whole is much more than the simple sum of its part despite the second law of thermodynamics if we manage to create a link between the local and the global keeping the homeostasis of the organisms and of the planet (the great organism).

3 Formalist computer science

Ignoring these concerns, Mitchell, Stiny, Yoshikawa, Coyne [SC90] tried to advance software in design and CAD proposing the atomic model language. Mitchell says design can be described by words that shape a language and such descriptions of words can be formalized using the first order predicate calculus notation. Here design is an epistemological event.  Its knowledge and application are separate and sequential. Knowledge precedes its application. The responses to the questions that happened in the situation are known previously. They do not change to adapt to peculiar demands. Theory precedes practice says Snodgrass and Coyne.

Likewise, the formalism of the shape grammars correspond directly to geometry; even nongeometric representations are mapped onto one or more geometric realizations. Shape grammars are applied to generate Palladian villas, Frank Lloyd Wright's prairie houses, Queen Anne houses, Japanese tea houses and other designs [Heis94].

Rosenman and Gero from the Key Centre of Design Computing, Department of Architectural and Design Sciences from University of Sydney generate architectural and structural design cooperatively.  Inspired by Bobrow about the function, behaviour, purpose and structure of a watch, they develop a model integrating the architect, mechanical engineer and structural engineer's views. Their integration means juxtaposition of visions in the style of arranging blocks and decorating façades. They implement certain abstractions in the C programming language, utilizing the class concept in an arbitrary way. The modeling of the multiple views is implemented in CAD [RG96].

Richard Coyne, the only architect of the research team in their center after realizing the failure of his logic models to generate design reacts and recognizes the hermeneutic nature of design.

4 Hermeneutic computer science

Although the formalist computer science is still the mainstream, there is a growing opposing trend in the artificial intelligence meetings and more recently in the object oriented paradigm through the introduction of design patterns and prototype-based object oriented languages. The formalist paradigm in philosophy and science orbits around centralization, control, hierarchy, predictability and 'provability'.  Its ideal model follows the atomic model language. Its visions are grounded in the philosophies of Descartes, Hobbes, Leibniz, Russell and Whitehead. Babbage, Turing and von Neumann illustrate the formalist philosophy in computer science. Newell, Simon and Minsky , in artificial intelligence.

Bo Dahlbom and Lars Mathiassen [DM97] adds that the romantic view grew out of a reaction against mechanistic thinking and was formulated towards the end of the 18th century, primarily by German philosopher-artists like Herder and Hegel (.....) Where the mechanists saw structures and systems, the romantics saw processes and change.  Likewise followers of the hermeneutic thinking emphasize autonomy, multiple perspective, self-organization, change, evolution, interpretation, malleability and flexibility.  They argue that any formal syntax fails in grasping the intrinsic properties of the natural world [West97].  Husserl, Heidegger, Gadamer, Vygotsky and Foucault represent this trend in philosophy as well as the contemporaries Maturana, Varela, Prigogine and Gell-Mann.  In computer science, it reflects in the viewpoints of Floyd and colleagues, Coyne, Dreyfus brothers and the post-artificial intelligence works from Winograd.

In the sixties, this trend was represented by the LISP exploratory programming; in the seventies, it moved to Prolog and in the eighties, to Smalltalk.  However, the object oriented paradigm behaves rather like a Janus head.  Hermeneutization begins to be introduced in the formalist world in parallel to object-oriented methods not hermeneutic [Aksi97]. And the confusion arises.

I believe hermeneutics has the nature of the rainbow, its colour gamut varies from infrared to ultraviolet and appears in the sky after the rain due to the diffraction of light. To try to mimic its composition, first dealing with the primary colours and then the secondary colours orange, green an purple will not lead to its circular shape ranging from red to ultraviolet and even less ignoring the need of interaction with light and water. An hermeneutic method has necessarily a holistic nature. It leads to diversity in unity.

5 The Model of Primary, Secondary and Tertiary Waves

The design and planning within an ecological context is essentially an interpretative activity.  It is an activity that belongs to the global understanding of a situation that must be aprehended while discrete entities defined by the situation and able to define the situation. It evolves in time and space. To keep pace with Gaia and shelter human life soundly, an urban ecosystem must care about the 'earth'from where comes everything (materials) and its surrounding environment that receives the incoming energy from the sun and the design of human behaviour. This it achieves by designing the environment in which behaviour occurs encompassing all environments form domestic, industrial to agricultural, medical, military, etc modeling basically the ergonomic and geotechnical dimensions. At the microlevel, the ergonomic dimension includes human-artifact interface technology or hardware ergonomics; human -environment interface technology or environmental ergonomics and user-system interface technology or software ergonomics and at the macrolevel, there is organization-artifact technology or macroergonomics. It is fundamental here that input comes from the layout of the plans pervaded by the needs of the human beings in interaction with the environment.

The geotechnical dimension guides the designer to receive the geological information given by first order observational maps (topographic, bedrock geology, geologic, tectonic and structure, agricultural soils, ground water, surface drainage); second-order (engineering) maps (unconfined compressive strength, rock quality, slope stability, excavation difficulty, infiltration capacity, corrosivity, soil quality, engineering soils classification, engineering resources) and third-order (interpretive) maps (geologic hazards, home site suitability, heavy construction suitability, subsurface installations suitability, resource suitability and waste disposal suitability) in terms of use suitability and not in terms of geologic processes or descriptions and thus information must be such that can be applied directly to sustainable policies of soil use management given by fourth-order (planning) maps (engineering geology recommended land use map).

The MPSTW (figure 1) derived from the application of catastrophe, semiotics

and graph theories deals gracefully with these dimensions. The primary waves work like a genotype dealing with the processes of interaction of the elements of the architectonic object and the environment through the hypotheses of homeostasis, continuity, differentiation and repeatability. The design processes are dealt by the secondary waves and act like phenotypes and involve a geometric intuition that creates a specific geometry to model the urban morphogenesis through tilings, discrete groups of the plane and fractals. To develop this submodel I demonstrate taht architectural design may be considered a language with its planes function and form and their stratas substance of the function, form of the function, substance of the form and form of the form. All these processes are applied to the elements of the architectural design, namely, environmental comfort (thermal comfort, acoustics, daylighting), activities, structural systems, hydraulic installations, etc. Its outcome is the eco-system with hyphen or the architectonic artifact. It has an autopoietic nature insofar as it grows from the smallest artifact (the building and support facilities) passing by the neighborhood and boroughs to the sustainable city and the bioregion. A finer granularity unravels through the subeco-system with hyphen or the sum of the processes applied to each element. They work out like the figures of a language (a sign is composed of figures). This partaking of the urban phenomenon especially through the hypothesis repeatability causes the emergence of the tertiary waves or the blending of design and planning. Or the eco-system with hyphen defines the the urban ecosystem and is defined by it. Moreover it allows the designer and the user to start modeling by any of the processes adding flexibility and malleability to the design and planning enhancing participation of the citizen.

6 Self

Hence the MPSTW falls within an hermeneutic trend. Indeed, its elements and processes behave themselves with dynamism and flexibility. They are not variations around a theme. Classes are useful when multiple instances of similar objects pervade the problem space. Hence sharing attributes among the objects as well as programming exploratorily is fundamental. The independence of each element or process suggests an object. Each object accepts or delegates tasks to the other. Each element and each process is unique. There is no need for classes No clear taxonomy for tasks is defined, hence little need for inheritance [Grog97]. Moreover, MPSTW is built for cooperative work among designers and citizens covering total synergetic interaction among its members.

Martin Abadi and Luca Cardelli [CA97] insist on that everything can be better represented in terms of objects, even functions and classes. The basic constructions are simpler, flexible and powerful. Hence naturally a prototype ased object oriented language tunes with the hermeneutic nature of design enhancing it Wegner insists on that objects, classes and inheritance are not orthogonal. Classes are defined in terms of objects, inheritance in terms of classes. The essence of a class can be defined independently of the object and the essence of inheritance independently of classes and objects [Wegn87].

Inheritance as a mechanism to share resources defined incrementally internalizing shared resources treat the latter as part of an extended self (identity). Hence the definition of inheritance in terms of a particular mechanism of self-reference enabling the internalization of remotely defined operations as part of the extended identity of the object is called delegation.

The delegation based languages allow the objects to share and internalize operations from ancestral objects called prototypes, that work as instances and templates for the descendents. Hence the prototypical languages are languages based on delegation that carry out delegation by prototypes. And the chosen language to implement MPSTW is Self, a prototype based object oriented language.

Ungar and Smith [SU95] emphasize the concreteness of the prototypes because they are examples of objects instead of format descriptions and initializations.

The shared behaviour by a family of objects is hold by a separate object that is the father of all the objects, even of the prototype. This way, the prototype is absolutely equal to any other member of the family. The object that contains the shared behaviour plays the role of a class, except that it only contains the shared behaviour without format information.These parent-objects are called traits-objects.

Self contains graphical objects called morphs that behave exactly like the object. Since MPSTW also has a graphical nature this feature is very relevant.

Acknowledgements

Joergen Lindskov Knudsen played a great role in paving the way for my firm introduction to hermeneutics. Indeed, the pattern construct in Beta and the Mjoelner environment put you nearer hermeneutic computer science than the other OO languages. Heartfelt thanks to the Beta Group. Erik Ernest and Paulo Ceneviva (EESC-USP) helped me an awful lot in the final version of this paper.

7. References

[Aksi97] Aksit, N.: Active software artifacts. Workshop Modeling Software Processes and Artifacts. ECOOP'97.

[Card97] Cardelli, L. and Abadi, M.: A theory of objects. Tutorial ECOOP'97.

[DM97] Dahlbom, B. and Mathiassen, L.: The future of our profession.CACM Vol.40, No.6, June 1997, 80-89

[Grog97] Grogono, P.: Messy solutions for messy problems. Paper position for Second Workshop on prototype-based object oriented programming . ECOOP'97. Finland. Jyväskylä.

[Heis94] Heisserman, J.: Generative geometric design. IEEE Computer graphics and applications. March 1994

[Joer92] Joergensen, S.E.: Integration of ecosystem theories: a pattern. Kluwer Academic Publishers. 1992

[RG96] Rosenman, M.A. and Gero, J.S.: Modelling multiple views of design objects in a collaborative CAD environment. Computer Aided Design, Vol.28, No.3

[Snod90] Snodgrass, A. and Coyne, R.: Is designing hermeneutical? Working paper. Faculty of Architecture and Urbanism. University of Sydney. 1990

[SU95] Smith, R.B. and Ungar, D.: Programming as an experience: the inspiration for Self. ECOOP'95. LNCS 952

[Wegn87] Wegner, P.: Dimensions of object-based language design. OOPSLA'87.