Knowledge and the Flow of Information: Preface
Dretske (Fred)
Source: Dretske - Knowledge and the Flow of Information, 1981
Paper - Abstract

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Preface (Full Text1)

  1. In the beginning there was information. The word came later. The transition was achieved by the development of organisms with the capacity for selectively exploiting this information in order to survive and perpetuate their kind.
  2. It is common to think of information as a much later arrival on the evolutionary2 scene, as something that depends on the interpretive efforts — and, hence, prior existence — of intelligent life. According to this view, something only becomes information when it is assigned a significance, interpreted as a sign, by some cognitive agent. Beauty is in the eye of the beholder, and information is in the head of the receiver. To speak of information as out there, independent of its actual or potential use by some interpreter, and antedating the historical appearance of all intelligent life, is bad metaphysics. Information is an artifact, a way of describing the significance for some agent of intrinsically meaningless events. We invest stimuli with meaning, and apart from such investment, they are informationally barren.
  3. This is one way of thinking about information. It rests on a confusion, the confusion of information with meaning. Once this distinction is clearly understood, one is free to think about information (though not meaning) as an objective commodity, something whose generation, transmission, and reception do not require or in any way presuppose interpretive processes. One is therefore given a framework for understanding how meaning can evolve, how genuine cognitive systems — those with the resources for interpreting signals, holding beliefs, and acquiring knowledge — can develop out of lower-order, purely physical, information-processing mechanisms. The higher-level accomplishments associated with intelligent life can then be seen as manifestations of progressively more efficient ways of handling and coding information. Meaning, and the constellation of mental attitudes that exhibit it, are manufactured products. The raw material is information.
  4. This, in very sweeping terms, is the thesis of the present work. It sounds ambitious. Too ambitious — something only a philosopher, ignorant of how little is really known about these matters, would seriously propose. Let me qualify it, therefore, by saying that what I have described is the object for which I am reaching, not, perhaps, the object I have succeeded in grasping. Readers will have to judge for themselves how far short of the goal I have fallen.
  5. One is accustomed to hearing cognitive psychologists and computer scientists, not philosophers, talk about information. Scientifically speaking, or so it would appear from the last thirty years, the cognitive exploits of a person, planarian3, or computer are to be understood in terms of complex information-handling processes. Philosophers, on the other hand, still seem disposed to think about knowledge, perception, memory, and intelligence with a completely different set of analytical tools: evidence, reasons, justification, belief, certainty, and inference. There is, consequently, a serious communication problem. Philosophers articulate theories of knowledge that, from the point of view of the cognitive sciences, appear to be irrelevant to the best available models of perception, learning, and recognition. And philosophers (with some notable exceptions) tend to ignore, disparage, or dismiss the scientist's computer programs, flow charts, and feedback loops as so much empirical chaff to his conceptual wheat. Without a common vocabulary with which to address the issues, this kind of isolation is inevitable. The result, I think, is an impoverishment of both.
  6. This, indeed, is one of the reasons I have selected the concept of information as the central idea around which to organize this philosophical study. If contact is to be made between philosophy and the wealth of relevant material in the cognitive sciences, then some bridges must be built, if only terminological bridges, between philosophical treatments of knowledge, belief, and perception and those scientific disciplines concerned with the same dimensions of our mental life.
  7. It is, of course, fashionable to talk about information. Magazine advertisements remind us that we live in an Age of Information. I am therefore sensitive to the charge that I have merely adopted a faddish terminological form in which to stuff less stylish philosophical substance. In a sense, I plead guilty to this charge. I have adopted, for philosophical purposes, a way of talking that has become prevalent in the cognitive sciences during the last few decades. This, though, is not all I have tried to do. I have also tried to put this way of talking on a philosophically respectable footing in order to illuminate some obscure areas in epistemology and the philosophy of mind.
  8. It is much easier to talk about information than it is to say what it is you are talking about. A surprising number of books, and this includes textbooks, have the word information in their title without bothering to include it in their index. It has come to be an all-purpose word, one with the suggestive power to fulfil a variety of descriptive tasks. Its use in telecommunications and computer technology gives it a tough, brittle, technical sound, and yet it remains spongy, plastic, and amorphous enough to be serviceable in cognitive and semantic studies. In thinking about information, one tends to think of something objective and quantifiable — the electrical pulses surging down a copper wire, for example — and, at the same time, of something more abstract, of the news or message that these pulses carry — something not so clearly objective and quantifiable. For many purposes this is a useful ambiguity. It allows one to speak, for example, of information being picked up, processed, and passed along to the higher cognitive centers where it is used to control an organism's response to its surroundings. One is given a picture of cells communicating with one another in something like the way you and I communicate with one another. An organism's cognitive efforts begin to sound like community projects undertaken by loquacious neurons. Such pictures are nourished by a convenient ambiguity in the terms used to describe such processes.
  9. For philosophical purposes something better is needed. It is not that philosophy is so much more precise, exact, or demanding than its scientific cousins. Quite the contrary. In most respects it operates with far fewer constraints on its theoretical flights. This book is a case in point. Nonetheless, the problems that define the study of philosophy are uniquely sensitive to conceptual issues. Getting straight about what one means is an essential first step. Words are the tools of philosophers, and if they are not sharp, they only disfigure the material.
  10. Therefore, I launch this study by examining, in Part I, the notion of information. I begin by looking at some of the fundamental ideas of communication theory. This is a useful way to begin, not because this theory (in its standard interpretation and application) tells us what information is. It does not. It does not even try. Rather, I begin here because the underlying structure of this theory, when suitably supplemented, can be adapted to formulate a genuinely semantic theory of information, a theory of information that can be used in cognitive and semantic studies. If, in accordance with communication theory, we conceive of information as an objective commodity, as something defined in terms of the network of lawful relationships holding between distinct events and structures, one can, or so I argue, develop a plausible, and theoretically powerful, analysis of a signal's informational content.
  11. Part II is an attempt to apply this idea of information to questions in the theory of knowledge. Knowledge is identified with information-caused belief. A discussion of skepticism follows. The skeptical challenge is given a slightly novel twist by casting the dispute in terms of different criteria for distinguishing between the information we receive over a channel and the channel over which we receive this information. Finally, in Chapter 6, I attempt to distinguish sensory processes on the one hand and cognitive processes on the other, between seeing a duck and recognizing it as a duck, in terms of the different way information about the duck is coded. Sensory processes are analog in nature; cognitive processes are digital.
  12. The final part of this book, Part III, is devoted to an analysis of belief, concepts, and meaning (insofar as this is understood to be a property of our psychological states). Frankly, I am the most apprehensive about these three chapters. There is so much relevant material about which I am ignorant — some of the work in developmental psychology, for instance — that I am prepared to see portions of this analysis condemned as factually inadequate. Given studies A, B, and C, that just is not, or could not be, the way things actually happen. Nevertheless, if the details are wrong, the general framework, I would argue, must be right. If physical systems are capable of developing concepts, with the consequent capacity for holding beliefs, both true and false beliefs — if such systems are capable of representing, and misrepresenting, the condition of their surroundings — then the internal structures that qualify as beliefs or representations must develop in something like the way I describe. I see no other way for meaning, the sort of content we ascribe to internal states when we attribute knowledge and belief, to evolve. But this, I admit, may be because I do not see very well.
  13. The entire project can be viewed as an exercise in naturalism — or, if you prefer, materialistic metaphysics. Can you bake a mental cake using only physical yeast and flour? The argument is that you can. Given the sort of information described in Part I, something that most reflective materialists should be willing to give, we have all the ingredients necessary for understanding the nature and function of our cognitive attitudes, all that is necessary for understanding how purely physical systems could occupy states having a content (meaning) characteristic of knowledge and belief. This, of course, does not show that human beings are nothing but complex physical systems, that the mind is really material, but it does show that for purposes of understanding one facet of our mental life, that having to do with our cognitive capabilities, it is not necessary to think of them as anything else.



In-Page Footnotes

Footnote 1: Highlighting ignored.

Footnote 3: This is a flatworm! See Wikipedia: Planarian.


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