Foundational Issues in Artificial Intelligence and Cognitive Science:
Impasse and Solution

Elsevier Science

Mark H. Bickhard
Lehigh University

Loren Terveen
AT&T Bell Laboratories

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The book focuses on a conceptual flaw in contemporary artificial intelligence and cognitive science. Many people have discovered diverse manifestations and facets of this flaw, but the central conceptual impasse is at best only partially perceived. Its consequences, nevertheless, visit themselves as distortions and failures of multiple research projects -- and make impossible the ultimate aspirations of the fields.

The impasse concerns a presupposition concerning the nature of representation -- that all representation has the nature of encodings: encodingism. Encodings certainly exist, but encodingism is at root logically incoherent; any programmatic research predicated on it is doomed to distortion and ultimate failure.

The impasse and its consequences -- and steps away from that impasse -- are explored in a large number of projects and approaches. These include SOAR, CYC, PDP, situated cognition, subsumption architecture robotics, and the frame problems -- a general survey of the current research in AI and Cognitive Science emerges.

Interactivism, an alternative model of representation, is proposed and examined.


The central point of Foundational Issues in Artificial Intellligence and Cognitive Science -- Impasse and Solution is that there is a conceptual flaw in contemporary approaches to artificial intelligence and cognitive science, a flaw that makes impossible the ultimate aspirations of these fields. Many people have discovered diverse manifestations and facets of this flaw, but the central conceptual impasse is only partially perceived. The consequences, nevertheless, visit themselves as distortions and failures of research projects across the fields.

The locus of the impasse concerns a common assumption or presupposition that underlies all parts of the field -- a presupposition concerning the nature of representation. We call this assumption "encodingism", the assumption that representation is fundamentally constituted as encodings. This assumption, in fact, has been dominant throughout Western history. We argue that it is at root logically incoherent, and, therefore, that any programmatic research predicated on it is doomed to distortion and ultimate failure.

On the other hand, encodings clearly do exist, and therefore are clearly possible, and we show how that could be -- but they cannot be the foundational form of representation. Similarly, contemporary encoding approaches are enormously powerful, and major advances have been made within these dominant programmatic frameworks -- but the encodingism flaw in those frameworks limit their ultimate possibilities, and will frustrate efforts toward the programmatic goal of understanding and constructing minds.

The book characterizes and demonstrates this impasse, discusses a number of partial recognitions of and movements away from it, and then traces its consequences in a large number of projects and approaches within the fields. These include SOAR, CYC, PDP, situated cognition, subsumption architecture robotics, and the frame problems. In surveying the consequences of the impasse, we also provide a general survey of the current research in AI and Cognitive Science per se.

We do not propose an unsolvable impasse, and, in fact, present an alternative that does resolve that impasse. This is developed for contrast, for perspective, to demonstrate that there is an alternative, and to explore some of its nature. We end with an exploration of some of the architectural implications of the alternative -- called interactivism -- and argue that such architectures are 1) not subject to the encodingism incoherence 2) more powerful than Turing machines, 3) more consistent with properties of central nervous system functioning than other contemporary approaches, and 4) capable of resolving the many problematics in the field that we argue are in fact manifestations of the underlying impasse.

The audience for this book will include researchers, academics, and students in artificial intelligence, cognitive science, robotics, cognitive psychology, philosophy of mind and language, natural language processing, connectionism, and learning. The focus of the book is on the nature of representation, and representation permeates everywhere -- so also, therefore, do the implications of our critique and our alternative permeate everywhere.



Mark H. Bickhard
Lehigh University
Loren Terveen
AT&T Bell Laboratories

Elsevier Science Publishers

Table of Contents
Preface                                                                 xi
Introduction                                                            1
A PREVIEW                                                               2

I  GENERAL CRITIQUE                                                     5

1  Programmatic Arguments                                               7

CRITIQUES AND QUALIFICATIONS                                            8
DIAGNOSES AND SOLUTIONS                                                 8
IN-PRINCIPLE ARGUMENTS                                                  9

2  The Problem of Representation                                        11

ENCODINGISM                                                             11
Circularity                                                             12
Incoherence - The Fundamental Flaw                                      13
A First Rejoinder                                                       15
The Necessity of an Interpreter                                         17

3  Consequences of Encodingism                                          19

LOGICAL CONSEQUENCES                                                    19
Skepticism                                                              19
Idealism                                                                20
Circular Microgenesis                                                   20
Incoherence Again                                                       20
Emergence                                                               21

4  Responses to the Problems of Encodings                               25

FALSE SOLUTIONS                                                         25
Innatism                                                                25
Methodological Solipsism                                                26
Direct Reference                                                        27
External Observer Semantics                                             27
Internal Observer Semantics                                             28
Observer Idealism                                                       29
Simulation Observer Idealism                                            30

SEDUCTIONS                                                              31
Transduction                                                            31
Correspondence as Encoding:
     Confusing Factual and Epistemic Correspondence                     32

5  Current Criticisms of AI and Cognitive Science                       35

AN APORIA                                                               35
Empty Symbols                                                           35

ENCOUNTERS WITH THE ISSUES                                              36
Searle                                                                  36
Gibson                                                                  40
Piaget                                                                  40
Maturana and Varela                                                     42
Dreyfus                                                                 42
Hermeneutics                                                            44

6  General Consequences of the Encodingism Impasse                      47

REPRESENTATION                                                          47
LEARNING                                                                47
THE MENTAL                                                              51
WHY ENCODINGISM?                                                        51

     AN ALTERNATIVE TO ENCODINGISM                                      53

7  The Interactive Model                                                55

BASIC EPISTEMOLOGY                                                      56
Representation as Function                                              56
Epistemic Contact: Interactive Differentiation and Implicit Definition  60
Representational Content                                                61

EVOLUTIONARY FOUNDATIONS                                                65

SOME COGNITIVE PHENOMENA                                                66
Perception                                                              66
Learning                                                                69
Language                                                                71

8  Implications for Foundational Mathematics                            75

TARSKI                                                                  75
Encodings for Variables and Quantifiers                                 75
Tarski's Theorems and the Encodingism Incoherence                       76
Representational Systems Adequate to Their Own Semantics                77
Observer Semantics                                                      78
Truth as a Counterexample to Encodingism                                79

TURING                                                                  80
Semantics for the Turing Machine Tape                                   81
Sequence, But Not Timing                                                81
Is Timing Relevant to Cognition?                                        83
Transcending Turing Machines                                            84

     ASSUMPTIONS AND CONSEQUENCES                                       87

9  Representation:  Issues within Encodingism                           89

Physical Symbol Systems                                                 90
The Problem Space Hypothesis                                            98
SOAR                                                                    100

PROLIFERATION OF BASIC ENCODINGS                                        106
CYC - Lenat's Encyclopedia Project                                      107

TRUTH-VALUED VERSUS NON-TRUTH-VALUED                                    118
Procedural vs Declarative Representation                                119

PROCEDURAL SEMANTICS                                                    120
Still Just Input Correspondences                                        121

SITUATED AUTOMATA THEORY                                                123

NON-COGNITIVE FUNCTIONAL ANALYSIS                                       126
The Observer Perspective Again                                          128

BRIAN SMITH                                                             130
Correspondence                                                          131
Participation                                                           131
No Interaction                                                          132
Correspondence is the Wrong Category                                    133

ADRIAN CUSSINS                                                          134

INTERNAL TROUBLES                                                       136
Too Many Correspondences                                                137
Disjunctions                                                            138
Wide and Narrow                                                         140
Red Herrings                                                            142

10  Representation:  Issues about Encodingism                           145

SOME EXPLORATIONS OF THE LITERATURE                                     145
Stevan Harnad                                                           145
Radu Bogdan                                                             164
Bill Clancey                                                            169
A General Note on Situated Cognition                                    174
Rodney Brooks: Anti-Representationalist Robotics                        175
Agre and Chapman                                                        178
Benny Shanon                                                            185
Pragmatism                                                              191
Kuipers' Critters                                                       195
Dynamic Systems Approaches                                              199

A DIAGNOSIS OF THE FRAME PROBLEMS                                       214
Some Interactivism-Encodingism Differences                              215
Implicit versus Explicit Classes of Input Strings                       217
Practical Implicitness: History and Context                             220
Practical Implicitness: Differentiation and Apperception                221
Practical Implicitness: Apperceptive Context Sensitivities              222
A Counterargument: The Power of Logic                                   223
Incoherence: Still another corollary                                    229
Counterfactual Frame Problems                                           230
The Intra-object Frame Problem                                          232

11  Language                                                            235

INTERACTIVIST VIEW OF COMMUNICATION                                     237

Awareness of the Context-dependency of Language                         240
Awareness of the Relational Distributivity of Meaning                   240
Awareness of Process in Meaning                                         242
Toward a Goal-directed, Social Conception of Language                   247
Awareness of Goal-directedness of Language                              248
Awareness of Social, Interactive Nature of Language                     252
Conclusions                                                             259

12  Learning                                                            261


LEARNING FORCES INTERACTIVISM                                           262
Passive Systems                                                         262
Skepticism, Disjunction, and the Necessity of Error for Learning        266
Interactive Internal Error Conditions                                   267
What Could be in Error?                                                 270
Error as Failure of Interactive Functional Indications -
     of Interactive Implicit Predications                               270
Learning Forces Interactivism                                           271
Learning and Interactivism                                              272

COMPUTATIONAL LEARNING THEORY                                           273

INDUCTION                                                               274

GENETIC AI                                                              275
Overview                                                                276
Convergences                                                            278
Differences                                                             278
Constructivism                                                          281

13  Connectionism                                                       283

OVERVIEW                                                                283
STRENGTHS                                                               286
WEAKNESSES                                                              289
ENCODINGISM                                                             292
     AI LANGUAGE APPROACHES                                             296

IV  SOME NOVEL ARCHITECTURES                                            299

14  Interactivism and Connectionism                                     301

Hybrid Insufficiency                                                    303

Distributivity                                                          304
Metanets                                                                307

15  Foundations of an Interactivist Architecture                        309

THE CENTRAL NERVOUS SYSTEM                                              310
Oscillations and Modulations                                            310
Chemical Processing and Communication                                   311
Modulatory "Computations"                                               312
The Irrelevance of Standard Architectures                               313
A Summary of the Argument                                               314

PROPERTIES AND POTENTIALITIES                                           317
Oscillatory Dynamic Spaces                                              317
Binding                                                                 318
Dynamic Trajectories                                                    320
"Formal" Processes Recovered                                            322
Differentiators In An Oscillatory Dynamics                              322
An Alternative Mathematics                                              323
The Interactive Alternative                                             323

V  CONCLUSIONS                                                          325

16  Transcending the Impasse                                            327

FAILURES OF ENCODINGISM                                                 327
INTERACTIVISM                                                           329
SOLUTIONS AND RESOURCES                                                 330
TRANSCENDING THE IMPASSE                                                331

References                                                              333
Index                                                                   367


Artificial Intelligence and Cognitive Science are at a foundational impasse which is at best only partially recognized. This impasse has to do with assumptions concerning the nature of representation: standard approaches to representation are at root circular and incoherent. In particular, Artificial Intelligence research and Cognitive Science are conceptualized within a framework that assumes that cognitive processes can be modeled in terms of manipulations of encoded symbols. Furthermore, the more recent developments of connectionism and Parallel Distributed Processing, even though the issue of manipulation is contentious, share the basic assumption concerning the encoding nature of representation. In all varieties of these approaches, representation is construed as some form of encoding correspondence. The presupposition that representation is constituted as encodings, while innocuous for some applied Artificial Intelligence research, is fatal for the further reaching programmatic aspirations of both Artificial Intelligence and Cognitive Science.

First, this encodingist assumption constitutes a presupposition about a basic aspect of mental phenomena -- representation -- rather than constituting a model of that phenomenon. Aspirations of Artificial Intelligence and Cognitive Science to provide any foundational account of representation are thus doomed to circularity: the encodingist approach presupposes what it purports to be (programmatically) able to explain. Second, the encoding assumption is not only itself in need of explication and modeling, but, even more critically, the standard presupposition that representation is essentially constituted as encodings is logically fatally flawed. This flaw yields numerous subsidiary consequences, both conceptual and applied.

This book began as an article attempting to lay out this basic critique at the programmatic level. Terveen suggested that it would be more powerful to supplement the general critique with explorations of actual projects and positions in the fields, showing how the foundational flaws visit themselves upon the efforts of researchers. We began that task, and, among other things, discovered that there is no natural closure to it -- there are always more positions that could be considered, and they increase in number exponentially with time. There is no intent and no need, however, for our survey to be exhaustive. It is primarily illustrative and demonstrative of the problems that emerge from the underlying programmatic flaw. Our selections of what to include in the survey have had roughly three criteria. We favored: 1) major and well known work, 2) positions that illustrate interesting deleterious consequences of the encodingism framework, and 3) positions that illustrate the existence and power of moves in the direction of the alternative framework that we propose. We have ended up, en passant, with a representative survey of much of the field. Nevertheless, there remain many more positions and research projects that we would like to have been able to address.

The book has gestated and grown over several years. Thanks are due to many people who have contributed to its development, with multitudinous comments, criticisms, discussions, and suggestions on both the manuscript and the ideas behind it. These include, Gordon Bearn, Lesley Bickhard, Don Campbell, Robert Campbell, Bill Clancey, Bob Cooper, Eric Dietrich, Carol Feldman, Ken Ford, Charles Guignon, Cliff Hooker, Norm Melchert, Benny Shanon, Peter Slezak, and Tim Smithers. Deepest thanks are also due to the Henry R. Luce Foundation for support to Mark Bickhard during the final years of this project.

Mark H. Bickhard
Henry R. Luce Professor of
Cognitive Robotics & the Philosophy of Knowledge
Department of Psychology
17 Memorial Drive East
Lehigh University
Bethlehem, PA 18015

Loren Terveen
Human Computer Interface Research
AT&T Bell Laboratories
600 Mountain Avenue
Murray Hill, NJ 07974


Identifies a fundamental premise about the nature of representation that underlies much of Cognitive Science -- that representation is constituted as encodings.

Explores fatal flaws with this premise.

Surveys major projects within Cognitive Science and Artificial Intelligence.

Shows how they embody the encodingism premise, and how they are limited by it.

Identifies movements within Cognitive Science and AI away from encodingism.

Presents an alternative to encodingism -- interactivism.

Demonstrates that interactivism avoids the fatal flaws of encodingisms, and that it provides a coherent framework for understanding representation.

Unifies insights from the various movements in Cognitive Science away from encodingism.

Sketches an interactivist cognitive architecture.


Cognitive Science
Simulation of Cognitive Processes
Artificial Intelligence, Knowledge Engineering, Expert Systems
Human Information Processing
Philosophy of Language
Philosophy of Mind
Cognitive Psychology
Artificial Life
Autonomous Agents
Dynamic Systems and Behavior
Theory of Computation

Bickhard, M. H., Terveen, L. (1995). Foundational Issues in Artificial Intelligence and Cognitive Science -- Impasse and Solution. Elsevier Scientific.

396 pages


ISBN 0 444 82520 7
US $97.00


ISBN 0 444 82048 5
US $150.00

In the US/Canada orders may be placed with:
Elsevier Science
P.O. Box 945
New York, NY 10159-0945
Phone (212) 633-3750
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