After a presentation of my chapter on "encyclopedic anxiety" Alice Marwick recommended David Foster Wallace's "Tense Present: Democracy, English, and the Wars Over Usage." I find the essay to be maddeningly frustrating: based on claims I absolutely agree with, he manages to find lines of argumentation that I think are very wrong. My notes from this essay are full of lengthy annotations. I agree that some works such as a usage dictionary or writers guide serve us well by being prescriptive: guiding us as to what is effective and accepted. (I'm slowly working my way through reading all of the Chicago Manual of Style, 15th edition, and enjoying it too! It is informative, pragmatic and useful in helping this writer address difficult questions.) However, this doesn't mean there's no room for descriptive reference works: telling us what is said or thought regardless of whether it is right or wrong according to someone's standard. Wallace is not willing to accept that description and prescription can coexist happily because he fears the Descriptivists then taint the larger culture and deprive SNOOTS such as himself the ability to tell others what is proper. He then makes a complete muddle of science:

If a physics textbook operated on Descriptivist principles, the fact that some Americans believe that electricity flows better downhill (based on the observed fact that power lines tend to run high above the homes they serve) would require the Electricity Flows Better Downhill Theory to be included as a "valid" theory in the textbook -- just as, for Dr. Fries, if some Americans use infer or implied, the use becomes an ipso facto "valid" part of language. Structural linguists like Gove and Fries are not, finally, scientists but census-takers who happen to misconstrue the importance of "the observed facts." It isn't scientific phenomenon they're tabulating but rather a set of human behaviors, and a lot of human behaviors are -- to be blunt -- moronic. (Wallace, p. 11).

He would also appreciate (and possibly hate) Wikipedia's NPOV which is descriptive in the way that he describes and objects to. In any case, he is confusing the method (i.e., scientific description) with a particular phenomenon (i.e., deterministic laws of physics, or less predictable patterns of human behavior). However, one might take a varied and subjective view of deterministic physical phenomena (e.g., a nonscientific poem about a falling acorn) or a scientific approach to more complex phenomenon (e.g., statistical inferences about human behavior, or complex nondeterministic phenomena).

On his point of stupidity, consider that to maintain that the earth is flat today might be considered moronic, but I don't go to Wikipedia (a largely descriptive undertaking) because it will tell me what is true -- you must look for that elsewhere -- but to understand what is understood about that theory including the contours and history of the flat-eathers. However, this doesn't mean Wikipedians must pretended that the earth is flat just to make some minority happy. Instead, one can also have completely descriptive statements that the theory is no longer supported by scientific authorities via references to authoritative sources. (And, here, Wikipedia does have a prescriptive bias in favoring references to authoritative sources within the materialistic/scientific worldview.) So, his metaphor seems backwards: the descriptive approach seems appropriate, and to some extent necessary, because human language is biased, and not a "law" in the same way that gravity is. To assume that the operation of gravity might reverse a century later violates a fundamental presumption of physics; but there is no such certainty in language use. Therefore, sometimes I might hear a word that I would never use myself for fear of giving offense, but I still might want to know its meaning: there is a role for a balance between prescriptive and descriptive.