But how do we begin?

From time to time I will grant readers a look at an actual question put to me by someone whose project I've edited. You will see my answer as well, although some funny stuff may get added here before I hit "Post." So, a first Q & A:

Q. There were a couple of edits that seem to violate generally accepted rules, as
far as I remember them - e.g. beginning a sentence with "And" or
"But" -- isn't that to be avoided?

A. It depends on the material. Back in the old days it used to be avoided without question. Now writing has changed. Many nonfiction works employ this, and you probably read examples every day without really noticing. It takes a smart editor to know the rules enough to "break" them. And I wonder whom I could be talking about. But I digress...