Those of us who love language are probably familiar with H. W. Fowler. I was practically brought up on his A Dictionary of Modern English Usage (the second edition, of course, edited by Sir Ernest Gowers). I rather like the firmness with which Fowler described the rules of correct English, although the Wikipedia entry says he provided a mix of the prescriptive (the old-style, stickler approach) and the descriptive (modern, politically correct).
I think I’m closer to the prescriptive end of the continuum, though I do acknowledge the evolving nature of language. (Good of me, you may think.) But I am aware of the pitfalls waiting for those who pride themselves on knowing some of the arcane rules of correct usage. As David Crystal says in his introduction to the reissued first edition,”You must always be watching your back.” See the New York Times essay by Jim Holt.