- "knowledge is a subset of belief. We believe many things, but only some of them are knowledge."
- "knowledge consists of beliefs that we have some good reason to believe."
- "knowledge consists of a body of truths that together express the truth of the world."
The fundamental problem I have with these claims is that what Weinberger identifies as different "characteristics of knowledge" per se, are actually different theories about knowledge held by different philosophers during the history of philosophy. Furthermore, Weinberger picks out only a small subset of the different theories. If you want to get a (very) rough idea of the broad range of available theories, take a look at the article on epistemology. Different theories of knowledge take different characteristics to be basic for knowledge. But, and this is important, it is a fundamental error to make any of these theories into basic characteristics of knowledge. Nor is it entirely clear that (i) and (ii) are compatible with (iii). In any case, the claim that "knowledge consists of a body of truths that together express the truth of the world" is a rather clumsy formulation of different tenets that may be held by a variety of (more conseervative) theories. It seems to be rather heavily indebted to the Feindbild (or strawman) of traditional metaphysics "developed" by Richard Rorty as an easy target of criticism. Rorty's views are as controversial as they are "interesting."
But the important point is that Weinberger commits another category mistake and mixes up theories about knowledge and characteristics of knowledge. In any case, on the most charitable reading, it can perhaps be said that Weinberger's claim amounts to saying that the Internet shows that certain theories of knowledge are shown by the new developments to be untenable. This is very different from saying that knowledge itself changed. The confusions do not augur well for the rest of the book.
1. I am well aware of the fact that if you accept a certain theory, you will also accept a certain set of characteristics as basic for knowledge. But Weinberger might have noticed how questionable such views are and how much the idea that knowledge is "justified true belief" has come under fire long before the Internet arose. See also some of the reactions to the previous post (and especially Michael Leddy's remark that Weinberger neglects, among other things, the difference.