If you shift an automatic while driving, will you damage your engine?

Here's an obvious but fundamental difference between people who learned to drive stick and those who've driven only ordinary automatics (a growing number, as traditional manuals disappear): Stick drivers are used to shifting while in motion. In an automatic, you shift only when stopped. Perhaps because of that, many drivers greet the idea of shifting while in motion with terror, fearing that they'll somehow blow up the engine or cause some awful mechanical shriek by sticking the car in neutral. Or worse, that they'll accidentally put it into reverse or park while cruising down the highway.

I'm here to tell you: Don't be afraid. After years as a driving instructor, and thanks to rental car companies that apparently lost their minds and let me loose with their vehicles, I can assure you: Your engine won't let you destroy it (at least not like this). And shifting into neutral at speed could save you from yourself.