Knowledge and the Flow of Information

Finally, a comment on the preceding review. The claim that meaning can be quantified is neither the main nor any other thesis of Dretske's book, and foisting it on him is wildly unfair. Drestke clearly and often distinguishes between the meaning of a sign and the information it carries. Moreover, his account of informational content certainly isn't just communication theory in disguise, as he hammers home time and again. As if this wasn't enough, early in chapter 2 Dretske explicitly rejects as absurd the claim that the amount of meaning in a message can be measured. Since warning lights of these kinds appear in the preface and regularly in every chapter thereafter, the preceding reviewer must indeed have found Dretske's (perfectly lucid) prose indigestible. There's every sign that he just hasn't bothered to digest it.


a classic   October 8, 2003
1 out of 4 found this review helpful

~It's kinda nonsense to call a thought nonsense without any argument against it. It is in fact a totally sensible position (actually many great philosophers hold it) to consider meaning as quantifiable.

This book is a classic of both epistemology and philosophy of mind. I don't agree with Dretske that our cognition is only concerned with digitalization, so that perception is mainly out of conceptualization. But the application of digital/analog distiction is really helpful to understand our~~ cognition in terms of information flowing. As one reader said, I really like this part of the book.

Also, his contribution to the definition of knowledge should not be neglected. There are a few philosophers who think of knowledge in terms of information, rather than in terms of justification. Although few people are interested with knowledge now, this line of thought is very intuitive and elegant.

It's been more than 20 years, since this book was published. But still, many parts of this~~ book help to understand more contemporary discussions of epistemology and philosophy of mind.~


Not the best application of "information theory".   June 20, 2006
Randall McCutcheon (Bexley, OH)
4 out of 4 found this review helpful

Information theory is highly relevant to issues in philosophy of language such as the nature of meaning; perhaps it is relevant to issues involving concept formation as well. This is a good book insofar as it recognizes this fact, which is seldom recognized. The result is thought-provoking and informative on the whole, though the author doesn't go far enough in reducing meaning to information and then in the latter part of the book he reveals some specious impetus for the project. The first is a mistake that is commonly made. Assertions partition sample spaces (indeed, they just *are* partitions of sample spaces), and their meaning as such is wholly constituted by this information-theoretic account. It would be a mistake to say that the entropy of the partition captures the whole of the information given by the partition, yes, but this doesn't imply that meaning has a non-information-theoretic character. It simply means you can't use a single number (the entropy) to express it. The second issue involves several misapplications of the very information theoretic principles Dretske espouses incorporation of in early chapters. To cite but one example (there are alas many as egregious here), Dretske asks us to accept that Tommy's assertion that this is a cup of "water" (Tommy was raised on Twin Earth) carries different information than yours or mine would, because on Twin Earth water can be XYZ. "...Earthlings acquired a different concept because their discriminatory responses were shaped by a different piece of information--the information, namely, that this was H2O." This is just wrong, as even an externalist about concepts can see immediately--the whole point of Putnam's thought experiment is that the information that it's H2O is just what's *not* playing any role here. It's not there in Tommy's assertion about the cup before him because it isn't even there in the visual and tactile experience under which Tommy forms his orginal concept of "water"; H2O and XYZ are indistinguishable under non-laboratory conditions. If you want to buy into the externalist picture, you have to do it in the face of information-theoretic arguments to the contrary--Dretske tries unsuccessfully to marshal information-theoretic arguments in support of a cause to which they are fundamentally inimical.

Although it's not completely related, one really should check out Fodor's "Psychosemantics" on Putnam/Burge.


Worst university press book I have ever read   February 25, 2000
Brad McCormick (Chappaqua, NY United States)
10 out of 59 found this review helpful

I was required to read this book in grad school (I was embarrassed for the teacher, since the selection reflects on the selector). It is a genuinely awful book. The style was (for me, at least) indigestible. The main thesis of the book, that *meaning* -- as opposed to bit configurations -- can be *quantified* is not just nonsense, but *frightening* nonsense, since quantifying everything gets funded these days. The book is worth buying if you want to discover how appalling what Joseph Weizenbaum described in his fine book: "Computer Power and Human Reason: From Judgment to calculation" can get!