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00100 CHAPTER 2--EXPLANATIONS AND MODELS
00200
00300
00400 It is perhaps as difficult to explain scientific explanation as it
00500 is to explain anything else. The explanatory practices of different
00600 sciences differ widely but they all share the purpose of someone
00700 attempting to answer someone else's why-how-what-etc. questions about
00800 a situation, event, episode, object or phenomenon. Thus explanation implies a
00900 dialogue whose participants share some interests, beliefs, and values.
01000 A consensus must exist about admissable and appropriate questions and answers. The participants
01100 must agree on what is a sound and reasonable question and what is a
01200 relevant, intelligible, and (believed) correct answer.
01300 The explainer tries to satisfy a questioner's curiosity by making
01400 comprehensible why something is the way it is. The answer may be a
01500 definition, an example, a synonym, a story, a theory, a model-description, etc.
01600 The answer satisfies curiosity by settling belief. Nnaturally the task of
01700 satifying the curiosity of a five year old boy is different from that
01800 of satisfying a forty year old psychiatrist.
01900 Suppose a man dies and a questioner (Q) asks an expainer (E):
02000 Q: Why did the man die?
02100 One answer might be:
02200 E: Because he took cyanide.
02300 This explanation might be sufficient to satisfy Q's curiosity and he
02400 stops asking further questions. Or he might continue:
02500 Q: Why did the cyanide kill him?
02600 and E replies:
02700 E: Anyone who ingests cyanide dies.
02800 This explanation appeals to a universal generalization under which
02900 is subsumed the particular fact of this man's death. Subsumptive explanations
03000 satisfy some questioners but not others who, for example, might want to
03100 know about the physiological mechanisms involved.
03200 Q: How does cyanide work in killing people?
03300 E: It stops respiration so one dies from lack of oxygen.
03400 If Q has biochemical interests he might inquire further:
03500 Q: What is cyanide's mechanism of drug action on the respiratory center?
03600 And so on, since there is no bottom to the questions which might be asked.
03700 Nor is there a top:
03800 Q: Why did the man take cyanide?
03900 E: Because he was depressed.
04000 Q: What was he depressed about?
04100 E: He lost his job.
04200 Q: How did that happen?
04300 E: The aircraft company let go most of their engineers because of the cut-back in defense contracts.
04400 Explanations are always incomplete because the top and bottom can be indefinitely
04500 extended and endless questions can be asked at each level.
04600 Just as the participants in explanatory dialogues
04700 decide what is taken to be problematic, so they also determine the termini of
04800 questions and answers. Each discipline has its characteristic stopping points.
04900 In explanatory dialogues there exist larger and smaller constellations
05000 to refer to which are taken for granted as a nonproblematic background.
05100 Hence in considering the function of paranoid thought `it goes without saying',
05200 that is, it transcends this particular field of function to say
05300 that a living teleonomic system as the larger constellation strives for
05400 maintenance and expansion of its life using smaller oriented, informed
05500 and constructive subprocesses. Also it goes without saying that at a lower
05600 level ion transport takes place through nerve-cell membranes. Every function
05700 of an organism can be viewed a governing a subfunction beneath and
05800 depending on a transfunction above which calls it into play for a purpose.
05900 Just as there are many alternative ways of describing, there are many
06000 alternative ways of explaining. An explanation is geared to some level
06100 of what the dialogue participants take to be the fundamental structures
06200 and processes under consideration. Since in psychiatry we cope with
06300 patients' problems using mainly symbolic-conceptual techniques,(it is true
06400 that the pill and the knife are also still available.),
06500 we are interested in aspects of human conduct which can be
06600 explained, understood, and modified at a symbol-processing level. Hence I shall
06700 attempt to explain paranoid conversational interactions by describing
06800 in some detail a simulation of paranoid interview behavior , having in
06900 mind an audience of mental health professionals and colleagues in fields
07000 of psychiatry, psychology, artificial intelligence, linguistics and philosophy.
07100 Symbol processing explanations postulate an underlying intentionalistic
07200 structure of hypothetical mechanisms, functions or strategies, goal-directed symbol-processing
07300 procedures, having the power to produce and being responsible for
07400 the manifest phenomena. In this ethogenic (generating behavior, Harre[ ]) approach the term "mechanism"
07500 is not used in the classical mechanical sense of the effects of forces on particles obeying laws of
07510 motion. Nor is it used in the sense of a mechanical contrivance such as a clock or an auto.
07600 Instead it is used here , and throughout the monograph,in the more general sense of modus operandi as
07700 in the mechanism for electing a president or the mechanism of evolutionary
07800 change. Thus I shall avoid the terms "mechanical" and "mechanistic" in order
07900 to avoid metaphors and images of Newtonian physics and contrivances. As will become clear,
08000 this ethogenic viewpoint uses the terms "mechanisms", "functions", "procedures"
08100 and "strategies" as roughly synonoymous.
08200
08300 2.2 Symbolic models
08400 An algorithm composed of symbolic computational
08500 procedures converts input symbolic structures into output symbolic
08600 structures according to certain principles. The modus operandi
08700 of a symbolic model is simply the workings of an algorithm when run on
08800 a computer. At this level of explanation, to answer `why?' means to provide
08900 an algorithm which makes explicit how symbolic structures go together,
09000 how they are organized to work to generate patterns of manifest phenomena.
09001
09100 To simulate the input-output behavior of a system using symbolic
09200 computational procedures, we construct a model which produces I/O
09300 behavior resembling that of the subject system being simulated. The
09400 resemblance is achieved through the workings of an inner postulated
09500 structure in the form of an algorithm, an organization of intentionalistic
09600 symbol processing procedures which are responsible for the characteristic
09700 observable behavior at the input-output level. Since we do not know the
09800 structure of the `real' simulative mechanisms used by the mind-brain,
09900 our postulated structure stands as an imagined theoretical analogue,
10000 a possible and plausible organization of mechanisms analogous to the
10100 unknown mechanisms and serving as an attempt to explain the workings
10200 of the system under study. A simulation model is thus deeper than a
10300 pure black-box explanation because it postulates functionally equivalent
10400 mechanisms inside the box to account for observable patterns of I/O
10500 behavior. A simulation model constitutes an interpretive explanation
10600 in that it makes intelligible the connections between external input
10700 internal states and output by postulating intervening symbol-processing procedures operating
10800 between symbolic input and symbolic output. An intelligible description
10900 of the model should make clear why and how it reacts as it does under
11000 various circumstances.
11100 To cite a universal generalization to explain an individuals behavior
11200 is unsatisfactory to a questioner who is interested in what powers and
11300 liabilities are latent behind manifest phenomena. To say `x is nasty
11400 because x is paranoid and all paranoids are nasty' may be relevant,
11500 intelligible and correct but it does not cite a structure which can account
11600 for `nasty' behavior as a consequence of input and internal states of
11700 a system. A model explanation specifies particular antecedants and mechanisms
11800 through which antecedants generate the phenomena. This ethogenic approach to
11900 explanation assumes perceptible phenomena display the regularities and
12000 irregularities they do because of the nature of a (currently) imperceptible
12100 and inaccessible underlying structure.
12200 When attempts are made to explain human behavior, principles in
12300 addition to those accounting for the natural order are invoked. `Nature
12400 entertains no opinions about us' said Nietsche but human natures do and
12500 therein lies a source of complexity for the understanding of human nature.
12600 Until the first quarter of the 20th century, natural sciences have been guided by the Newtonian ideal
12700 of perfect process knowledge about inanimate objects whose behavior can
12800 be subsumed under lawlike generalizations. When a deviation from a law was
12900 noticed,it was the law which was modified, since by definition physical objects do not have the power to break laws.
13000 When the planet Mercury was observed to deviate from the orbit predicted
13100 by Newtonian theory, no one accused the planet of being an intentional agent
13200 breaking the law; something was wrong with the theory. Subsumptive explanation is the acceptable norm in physics
13300 but it is seldom satisfactory in accounting for the behavior
13400 of living intentionalistic systems. In considering the behavior of falling bodies
13500 no one nowadays follows the Aristotelian pattern of attributing an intention
13600 to fall to the object in question. But in the case of living systems, especially
13700 ourselves, our ideal explanatory practice remains Aristotelian in utilizing
13800 a concept of intention.(Aristotle was not wrong about everything).
13900 Consider a man participating in a high-diving contest. In falling towards
14000 the water he falls at the rate of 32 feet per second per second. Viewing
14100 the man simply as a falling body, we explain his rate of fall by appealing to a physical
14200 law. Viewing the man as a human intentionalistic agent, we explain his dive as the result
14300 of an intention to dive in a cetain way in order to win the diving contest.
14400 His action (in contrast to mere movement) involves an intended following
14500 of certain conventional rules for what is judged by humans to constitute, say,
14600 a swan dive. Suppose part way down he chooses to change his position in
14700 mid-air and enter the water thumbing his nose at the judges. He cannot break
14800 the law of falling bodies but he can break the rules of diving and make a
14900 gesture which expresses disrespect and which he believes will be interpreted
15000 as such by the onlookers. Our diver breaks a rule for diving but follows
15100 another rule which prescribes gestural action for insulting behavior.
15200 To explain the actions of diving and nose-thumbing, we
15300 would appeal, not to laws of natural order, but to an additional order, to
15400 principles of human order, superimposed on laws of natural order and which
15500 take into account (1)standards of appropriate action in certain situations
15600 and (2) the agents inner considerations of intention, belief and value
15700 which he finds compelling from his point of view.
15800 In this type of explanation the explanandum, that which is being explained
15900 is the agent's informed actions, not simply his movements. When a human
16000 agent performs an action in a situation, we can ask:(1) is the action
16100 appropriate to that situation and if not, why did the agent believe his
16200 action to be called for.
16300 As will be shown, symbol-processing explanations rely on concepts
16400 of action, intention, belief, affect, preference, etc. These terms are
16500 close to the terms of ordinary language as is characteristic of early
16600 stages of explanations. It is also important to note that such terms are commonly utilized
16700 in describing computer algorithms in which final causes guide efficient causes. In
16800 an algorithm these ordinary terms can be explicitly defined and
16900 represented.
17000 Psychiatry deals with the practical concerns of inappropriate action,
17100 belief, etc. on the part of a patient. His behavior may be inappropriate
17200 to the onlooker since it represents a lapse from the expected, a
17300 contravention of the human order. It may even appear this way to the
17400 patient in monitoring and directing himself.But sometimes, as in severe cases of the paranoid mode
17500 the patient's behavior does not appear anomalous to himself. He maintains
17600 that anyone who understands his point of view, who conceptualizes
17700 situations as he does from the inside, would consider his outer behavior
17800 appropriate and justified. What he does not understand or accept is
17900 that his inner conceptualization is mistaken and represents a misinterpretation
18000 of the events of his experience.
18100 The model to be presented in the sequel constitutes an attempt to
18200 explain some regularities and particular occurrences of conversational
18300 paranoid phenomena observable in the clinical situation of a psychiatric
18400 interview. The explanation is at the symbol-processing level of
18500 linguistically communicating agents and is cast in the form of a dialogue
18600 algorithm. Like all explanations it is only partially accurate, incomplete
18700 and does not claim to represent the only conceivable structure of mechanisms.
18800
18900 2.3 The nature of algorithms
19000
19100 Theories can be presented in various forms such as natural language
19200 assertions, mathematical equations and computer programs. To date most
19300 theoretical explanations in psychiatry and psychology have consisted
19400 of natural language essays with all their well-known vagueness and
19500 ambiguities.Many of these formulations have been untestable, not because
19600 relevant observations were lacking but because it was unclear what
19700 the essay was really saying. Clarity is needed.
19800 An alternative way of formulating psychological theories is now
19900 available in the form of ethogenic algorithms, computer programs, which have
20000 the virtue of being clear and explicit in their articulation and which
20100 can be run on a computer to test internal consistency and external correspondence with the data of observation.
20200 Since we do not know the `real' mind-brain algorithms,
20300 we construct a theoretical model which represents a partial
20400 paramorphic analogue. (See Harre, 1972). The analogy is at the symbol-
20500 processing level, not at the hardware level. A functional, computational
20600 or procedural equivalence is being postulated. The question then becomes
20700 one of determining the degree of the equivalence. Weak functional equivalence
20800 consists of indistinguishability at the outermost input-output level.
20900 Strong equivalence means correspondence at each inner I/O level, that is
21000 there exists a match not only between what is being done but how it is
21100 being done at a given level of operations.(These points will be discussed
21200 in greater detail in Chapter 3).
21300 An algorithm represents an organization of symbol-processing mechanisms or functions
21400 which represent an `effective procedure'. It is essential here to grasp this concept.
21500 An effective procedure consists of two ingredients:
21600 (1) A programming language in which procedural rules of behavior
21700 can be rigorously and unambiguously specified.
21800 (2) A machine processor which can rapidly and reliably carry out
21900 the processes specified by the procedural rules.
22000 The specifications of (1), written in a formally defined programming
22100 language, is termed an algorithm or program while (2) involves a computer
22200 as the machine processor, a set of deterministic physical mechanisms
22300 which can perform the operations specified in the algorithm. The
22400 algorithm is called `effective' because it actually works, performing
22500 as intended when run on the machine processor.
22600 It is worth remphasizing that a simulation model postulates
22700 procedures analogous to the real and unknown procedures. The analogy being
22800 drawn here is between specified processes and their generating systems.
22900 Thus
23000
23100 mental process computational process
23200 --------------:: ----------------------
23300 brain hardware computer hardware and
23400 and programs programs
23500 The analogy is not simply between computer hardware and brain wetware.
23600 We are not comparing the structure of neurons with the structure of
23700 transisitors; we are comparing the organization of symbol-processing
23800 procedures in an algorithm with symbol-processing procedures of the
23900 mind-brain. The central nervous system contains a representation of
24000 the experience of its holder. A model builder has a conceptual representation
24100 of that representation which he demonstrates in the form of an algorithm.
24200 Thus an algorithm is a demonstration of a representation of a representation.
24300 When an algorithm runs on a computer the postulated explanatory
24400 structure becomes actualized, not described. (To describe the model
24500 is to present , among other things, its embodied theory). A simulation model such as the
24600 one presented here can be interacted with by a person at the linguistic
24700 level as a communicating agent in the world. Its symbolic communicative behavior
24800 can be experienced in a concrete form by a human observer-actor.
24900 Thus it can be known by acquaintance, by first-hand knowledge, as well
25000 as by the second-hand knowledge of description.
25100 Since the algoritm is written in a programming language, it is hermetic
25200 and opaque except to a few people, who in general do not enjoy reading
25300 other people's code. Hence the intelligibility requirement for explanations
25400 must be met in other ways. In an attempt to open the model to scrutiny
25500 I shall describe the model in detail using diagrams and interview
25600 examples profusely.