When I was in elementary school I was taught that if you have a noun that ends in `s’, and you want to make that noun possessive, you do it by placing an apostrophe at the end of the word and that is all. Thus, in referring to the theorem proved by Thomas Bayes, you would write Bayes’ theorm. In referring to the book wirtten by Richard Dawkins, you would write Dawkins’ book.
Lately, though, several people have told me that this is not correct. Apparently we are now supposed to place an `apostrophe s’ at the end of all nouns, regardless of whether or not the word already ends in `s’. Thus, I would write Bayes’s theorem or Dawkins’s book. It would seem that if I want to refer to the beauty of the game of chess, I now have to write chess’s beauty, which rather creates the impression that the `s’ key is sticking.
Nonetheless, in matters punctuational I am most definitely a conformist. So if this is what I must do then so be it. What do you think?