How And Why To Keep A “Commonplace Book”

The other day I was reading a book and I came across a little anecdote. It was about the great Athenian general Themistocles. Before the battle of Salamis, he was locked in a vigorous debate with a Spartan general about potential strategies for defeating the Persians. Themistocles was clearly in the minority with his views (but which ultimately turned out to be right and saved Western Civilization). He continued to interrupt and contradict the other generals. Finally, the Spartan general threatened to strike Themistocles if he didn’t shut up and stop. “Strike!” Themistocles shouted back, “But listen!”

When I read this, I immediately began a ritual that I have practiced for many years–and that others have done for centuries before me–I marked down the passage and later transferred it to my “commonplace book.” Why? Because it’s a great line and it stood out to me. I wrote it…