...He divides commentators on language into linguists, who are goodies, and pedants, who are baddies. Linguists describe how language is at the moment; pedants prescribe how they think it should be. Kamm's case against the pedants is compelling. They think that English is really Latin, only with different words, so that to them aggravate is really ad graviorem, meaning, towards something worse. They don't notice when Thomas More or Milton use the word infer when nowadays we're supposed to use imply. They peddle made-up rules about prepositions, and don't appear to know how well written English managed without the possessive apostrophe for most of its history. In short, he wants these blighters to stop grinding you down...
http://www.telegraph.co.uk/culture/books/bookreviews/11408186/Accidence-Will-Happen-the-Non-Pedantic-Guide-to-English-Usage-by-Oliver-Kamm.html