I love quotations, proverbs, aphorisms, teaching stories, koans, true rules, and Secrets of Adulthood. I especially love any single line that’s able to capture a complex idea in a simple phrase or image.

A few years ago, I was speaking at a big happiness conference in Sydney, Australia. During the course of a conversation with another panelist, I happened to quote something that no one in the audience seemed to know.

After a comment I made, I added, “Even a dog distinguishes between being stumbled over and being kicked.” I was astonished when the audience exploded with laughter. I thought this was a very well-known line, but they’d never heard it before.

It’s a line from The Common Law by Oliver Wendell Holmes, by the way.

Their reaction reminded me of the deep truth of this observation, and of the elegance of this expression of it. When someone injures us, we know very well – and we care a lot – about whether that injury was an unfortunate accident or a deliberate act. And the distinction matters a lot to our response.

And if we’re feeling bad about something we accidentally did that hurt someone else, it can be comforting to think, well, it was a stumble, but it wasn’t a kick.

Even a dog distinguishes between being stumbled over and being kicked.