Here is an indispensable text and reference book for anyone interested in a systems approach to environmental studies. It will be useful not only to geographers but also to ecologists and other environmental scientists; planners; economists and other social scientists; philosophers; and applied mathematicians.
Bennett and Chorley's book has a number of broad aims: first, to employ the systems approach to provide an interdisciplinary focus on environmental structures and techniques; second, to use this approach to aid in developing the interfacing of social and economic theory with physical and biological theory; and third, to investigate the implications of this interfacing for human response to current environmental dilemmas, and hence to expose the technological and social bases of values which underlie our use of natural resources.
Interpreting the "environment" so as to embrace physical, biological, man-made, social, and economic reality, the authors show that the systems approach provides a powerful vehicle for the statement of environmental situations of ever-growing temporal and spatial magnitude, and for reducing the areas of uncertainty in our increasingly complex decision making arenas.
Originally published in 1979.
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Philosophy, Analysis and Control
By Robert John Bennett, Richard J. Chorley
PRINCETON UNIVERSITY PRESSCopyright © 1978 R. J. Bennett and R. J. Chorley
All rights reserved.
The philosophy of environmental systems
Once upon a time there was a rajah in this region who called to a certain man and said: 'Gather together in one place all the men in Savatthi who were born blind ... and show them an elephant.'
'Very good, sire,' said the man, and did as he was told and said to them, 'O blind, such as this is an elephant' - and to one man he presented the head of the elephant, to another its ears, to another a tusk, to another the trunk, the foot, back, tail, and tuft of the tail, saying to each one that that was the elephant....
Thereupon, brethren, that rajah went up to the blind men and said to each: 'Tell me, what sort of thing is an elephant?' Thereupon those who had been presented with the head answered, 'Sire, an elephant is like a pot.' And those who had observed an ear only replied, 'An elephant is like a winnowing basket.' Those who had been presented with a tusk said it was a plowshare. Those who knew only the back, a mortar; the tail, a pestle; the tuft of the tail, just a broom.
Then they began to quarrel, shouting 'Yes, it is!' 'No, it is not!' 'An elephant is not that!' 'Yes, it's like that!' and so on, till they came to fisticuffs over the matter. Then, brethren, that rajah reflected deeply upon the scene.
Udana, IV, 6
Vicar: With God's help you have made this garden a thing of beauty.
Gardener: You should 'ave seen it when 'e 'ad it to 'isself!
I.I Systems and philosophy
A system is a set of logical operations acting upon, and acted upon by, one or more inputs. These inputs lead to the production of outputs from the system and this process of throughput is capable of either sustaining the operational structure of the system, or of transforming it, perhaps catastrophically. Inputs, throughputs and outputs of systems can involve flows of mass, energy, information or ideas, depending on the manner in which the system is defined. The process by which this definition takes place is often difficult to identify, and philosophers have long distinguished between modes of thought which view systematic associations of phenomena as dictated by nature itself, or as identified by man for his convenience. The most distinguished precedents for the former approach are provided by Aristotle and Plato who believed that knowledge of the external world could be certain and eternal because it was concerned with the essential form and structure of unified parts of reality from which their determinate processes or throughputs could be deduced. Plato's vivid expression of the route to true understanding in the Simile of the Cave depicts Man as bound by perceptions of the 'shadows' of reality which can be dispelled only by pure thought and reason (fig. I.I). In the Simile of the Divided Line this theme is further developed to a categorization of orders of understanding: from knowledge based on pure reason to opinion] based on shadowy understanding of the physical world (fig. 1.2) which should be unfettered to yield greater degrees of truth (Lee 1955). Aristotle believed that progress in the understanding of the world depends on one's ability to define the essential attributes of the forms with which we are presented and then, by examining the structures and interrelationships of these forms, to deduce the processes of which they are the tangible expressions (Grene 1963). He wrote, 'the principal object of natural philosophy is not the material elements, but their composition, and the totality of the form, independently of which they have no existence ...' so that 'the structures found are always of determinate processes, functioning in determinate contexts'. A number of points of importance immediately emerge from this viewpoint: firstly, that reality should be studied in terms of operating entities; secondly, that these entities have objective and eternal existence, irrespective of the observer, and thus form the basis for the formulation of universal laws; and, thirdly, that the ultimate objects of study should not be the forms or artefacts produced by the operations of systems, but the operation itself. Aristotle's opinion that reality can be properly studied from the point of view of its self-justified parts has been termed one of 'immanent teleology'. Modern developments of the classical view combine either Francis Bacon's concern for empiricism and hypothesis testing or Popperian falsification with mathematical deduction as in Russell and Wittgenstein. This is based on universal doubt which is used to build up universal principles from initial tangibles (for example, one's own existence as in the Cartesian Cogito ergo sum'). From such axioms flow necessary conclusions. The aim is Aristotelian in seeking knowledge of the world independent of the observer, but uses the hypothetico-deductive method (or positivism) rather than pure reason.
Opposed to this view are those who either deny the objectivity of reality or point to its irrelevance when faced with the partiality of man's perception of it. This attitude, too, is dignified by antiquity, for the Epicureans believed that 'things are exactly as they appear to be to our senses, or rather as they would appear to be if our senses were slightly more accurate' (Latham 1951, p. 10). The attitude of Dewey is most expressive of the philosophy of the subjectivity of reality and he wrote, 'meaning ... is not a psychic existence; it is primarily a property of behavior' (1958, p. 179). Although, with Aristotle, Dewey was concerned with the identification and examination of systematic entities, he believed in the essential subjectivity of the entities and wrote, 'inquiry is the controlled or directed transformation of an indeterminate situation into one that is so determinate in its constituent distinctions and relations as to convert the elements of the original situation into a unified whole' (quoted in Russell 1946, p. 851). The philosophy of Dewey has, indeed, been as influential among pure scientists as among social scientists, Whitehead (1957, p. 47) asserting that 'we must not slip into the fallacy of assuming that we are comparing a given world with given perceptions of it' and Bridgman (1954, p. 37) that 'it is in fact meaningless to try to separate observer and observed, or to speak of an object independent of an observer, or, for that matter of an observer in the absence of objects of observation.' Perhaps the most extreme statement of this subjective view of natural systems was given by Van Uexküll (1926, pp. ix-xv) as follows:
Nature imparts no doctrines: she merely exhibits changes in her phenomena. ... The sole authority for a doctrine is not Nature, but the investigator, who has himself answered his own questions ... the objects that surround us are constructed from the sense-qualities: and, indeed, one person uses some sense-qualities for the making of objects, and another uses others. So for him there are nothing but signs or indications for his subjective use, and they assert nothing whatever with regard to the phenomenon that is independent of him. ... No attempt to discover the reality behind the world of appearance, i.e. by neglecting the subject, has ever come to anything, because the subject plays the decisive role in constructing the world of appearance, and on the far side of that world there is no world at all.
In the two foregoing examples one can see rather extreme statements of viewpoints which are currently active in environmental studies. The former, termed 'logical positivist', is clearly associated with the 'scientific' type investigations, whereas the latter, or 'subjective behaviourist', is identified with man-centred social or psychological studies. Indeed, it might be argued that there is a basic difference between the objects of these two types of investigation, in that the former uses the mind of man to illuminate an objective reality, whereas the latter employs man's subjective vision of reality to study the variety of imagination exhibited by the human mind. Perhaps this is a fundamental distinction between science and art (fig. 1.3). The paintings of Turner and Van Gogh tell us, after all, a great deal more about the character of the minds of these creative artists than about the landscapes of England and France. In geography the first wave of the 'New Geography' was dominantly logical positivist in character, whereas since the middle 1960s something of a behavioural backlash has occurred. For example, in a recent work on 'the affective bond between people and place' Tuan (1974) has drawn attention to the following key behavioural terms:
Perception: 'Both the response of the senses to external stimuli and purposeful activity in which certain phenomena are clearly registered while others recede in the shade or are blacked out.'
Attitude: A cultural stance vis-à-vis the world.
World view.A belief system involving conceptualized experience, partly personal, largely social.
Tuan (1974, p. 248) concluded that man's environmental aspirations lie somewhere between the above approaches: 'Human beings have persistently searched for the ideal environment ... [drawing] on two antipodal images: the garden of innocence and the cosmos. ... So we move from one to the other ... seeking a point of equilibrium that is not of this world. '
It would be incorrect, however, to draw too broad a distinction between the structural and behavioural approaches, for both of them insist on the necessity of studying viable entities. From this point of view it is often of marginal significance whether these entities represent external natural truths or fortuitous erections of the mind of man. Again, both approaches stress the interdependence of the real world in its broadest sense, but recognize, with Aristotle, that the first necessary step in achieving knowledge is to separate the subject of study from the rest of existence (Grene 1963, p. 86). In systems terms this introduces us to the notion of bounded and unbounded systems. For our purposes a bounded system is one whose operation is entirely justified by its internally specified parts and relationships such that, if inputs occur, the resulting changes within the system and the outputs are capable of exact and unique prediction, given a perfect knowledge of the system. An input into a bounded system where output is inhibited is inevitably followed by a progressive equalization within the system and a breaking down of internal differentiation and of the structural hierarchies which are associated with the so-called increase in entropy. The level of entropy - i.e. of homogeneity, randomness or lack of free energy-thus uniquely describes the state of a bounded system. An unbounded system, on the other hand, is one whose internal operation is not solely controlled by input and output, but also by other real world influences. An unbounded system cannot be considered apart from the other systems which intersect it, with which it shares components, and the operations of which make the effect of inputs into the open system to a degree indeterminate, both in respect of outputs and of internal organization of the system. Unbounded systems are thus sustained in a structured and hierarchically organized state by repeated inputs (i.e. applications of' negative entropy'). It is clear from the foregoing that, with the possible exception of the universe itself, no truly bounded systems exist. However, from the problem-solving point of view it is convenient to assume that systems have been identified, either objectively or subjectively, and that their dominant behaviour can reasonably lead to the assumption of their bounding to all intents and purposes. Such assumptions form the basis of all observational and experimental scientific work. External influences are subsumed by the introduction of error terms which make up the deficiency between the actual and predicted behaviour of an unbounded system which has been investigated as if it were bounded.
A further aspect of systems analysis makes possible links with philosophical modes of thought and logical systems, and this involves the identification of the system's executive(Churchman 1971). The executive is that part of a system which determines: the functions of the other parts of the system, the circumstances under which each part is employed, and which is capable of judging system performance (Churchman 1971, p. 27). Judging or control systems have been an important inspiration to man's thinking at least since classical times (Mayr 1970) and the impetus has quickened with the nineteenth century development of the mathematical theory of control systems (Airy 1840, Maxwell 1867-8) to encompass abstract topological and morphogenetic features (Thom 1975). These mathematical developments discussed further in Chapters 3 and 4 derive from studies in biology (Lotka 1956), but more especially from the construction of automatic control devices such as wind machines (Lee 1747) and the Watt governor shown in fig. 1.4. This latter regulates the steam feed as input into a physical system (steam engine) designed to generate a given output (work). Mathematical developments also derive from the complex problems of inertial navigation of space vehicles, missile tracking and avoidance, and the complexities of control of large industrial plants. The executive in such systems determines the functions of subsystem components by manipulation of controllable physical inputs. The inspiration which mathematical control systems offer is as a means of determining attributes of controllability and observability, the categorization of the executive as the operator or steward over systems of nature, and the concentration on performance of systems defined by anthropocentric criteria. Hence they blur still further the distinction of Aristotelian abstract systems and perceptual subjectivism. The executive is the most important element in such systems.
A major function of the executive is to regulate and dispose inputs into the system and Churchman (1971, pp. 25-7) has restated Spinoza's (1677) four types of information processing as a 'taxonomy of inquiring systems', based on the role of the executive (fig. 1.5):
(a) Hearsay: A system which will input, store and retrieve (i.e. output from core) anything which it is programmed to do. It has a weak executive routine operating on a simple classificatory basis.
(b) Vague experience: A system whose executive rules, however complex and flexible, are independent of the intellect and exhibit no intellectual curiosity. Pattern recognition machines are of this type.
(c) Deductive: A system whose executive is adaptable to the extent of deciding whether a method of proof is likely to succeed or not according to predetermined rules (e.g. game playing machines) but which cannot question the inputs or create new methods of proof.
(d) Free intuitive: A system based on intuition leading to knowledge which arises though the essence of the object perceived, such that the executive has a valid theory to explain why knowledge (i.e. inputs into the inquiring system) occurs. In such a system the executive has a key role in filtering and organizing the information inputs from the real world.
For Churchman (1971) it is possible to distinguish between major philosophical modes of thought, or 'inquiring systems', by employing a systems format based on the role of the executive (fig. 1.6). We might use the term core for the rest of the system which contains facilities for storage, manipulation and output of information processed and input by the executive.
The Aristotelian inquiring system is dominated by a search for the externally defined 'essential attributes' which form the structural keys to the definition of the total structure-process relationships which is the goal of scientific investigation. Locke's (1690) philosophy involves a very weak executive with outside influences (i.e. expert opinion) determining which information should be taken most seriously, and with the input being processed by devices having no built-in preconceptions of the world and no a priori information about nature. These devices, or logical operators, combine the information into categories from which are developed consistent expositions (Churchman 1971, pp. 33, 99, 177). The inquiring system of Leibniz (1714) can be viewed as the most conventionally 'scientific'. It has strong executive control in that it is assumed that the system possesses innate ideas (a similar notion to that of Plato) which act upon the input stream of information to filter it into tautologies, self-contradictions and contingent truths. These latter are admitted to the core where they are constructed into fact nets-i.e. into expanded sets of contingent truths, interlinked by appropriate relationships - by a process of testing, ranking, building and linking. The purpose of the Leibniz system is to develop ever-expanding fact nets by filtering contingent truths with the aid of the innate executive, without the control of which the uncurbed imagination could create fantastic and mythical fact nets of any kind or size. Leibniz believed that the object of philosophy is to produce ever larger and more improved fact nets which converge upon an optimum reality. In this he mirrors the contemporary scientist's belief that there is an accurate image of nature which is being converged upon by improved approximations of fact and theory. A very different inquiring system of Hegel and Kant held that an objective information input can only be obtained if the inquirer has chosen the correct 'image of the world' (Weltanschauung) or the way of viewing the entire system (Churchman i97i,pp. 35,30-41,95-7 and 170-7). The mind should be loaded with a wealth of information and experiences so as to generate a deep conviction as to the operation of the real world. This conviction is believed to be a necessary stage of inquiry into reality and naturally operates an exceptionally strong executive control on the information which is admitted to the core as being consistent with the appropriate Weltanschauung. Here it is interrogated as to why the inquirer holds his thesis with such conviction. The system then generates a diametrically opposed antithesis and conducts a confrontation, along the lines of Kantian dialectic, leading to a more refined and higher level of world image (or synthesis) which is then subjected to a process of feedback whereby the output of the inquiring system feeds back to influence subsequent inputs of information. Feedback may either reinforce the input in an explosive manner or dampen it. The philosophical system of Dewey has been compared with that of Hegel in that in an attempt to identify unified wholes, often by biological analogy, he erects initial hypotheses which act as strong executive controls over the input of information and its interpretation. As Santayana put it: 'In Dewey ... there is a ... tendency to dissolve the individual into his social functions, as well as everything substantial and actual into something relative and transitional' (quoted in Russell 1946, p. 855).
Excerpted from Environmental Systems by Robert John Bennett, Richard J. Chorley. Copyright © 1978 R. J. Bennett and R. J. Chorley. Excerpted by permission of PRINCETON UNIVERSITY PRESS.
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Table of Contents
- Frontmatter, pg. i
- Contents, pg. v
- Acknowledgements, pg. viii
- Preface, pg. xi
- 1. The philosophy of environmental systems, pg. 1
- 2. Systems methods, pg. 25
- 3. Control systems, pg. 94
- 4. Space-time systems, pg. 152
- 5. Cognitive systems, pg. 223
- 6. Decision making systems, pg. 250
- 7. Physico-ecological systems, pg. 319
- 8. Socio-economic systems, pg. 399
- 9. Systems interfacing, pg. 467
- 10. Conclusion: future problems, pg. 541
- Appendices, pg. 554
- References, pg. 566
- Index of persons, pg. 599
- Subject index, pg. 607