Quotable Gems

I—like many of you, I'm sure—collect quotable quotes. Especially interesting to me are those from the pens of mystery authors. A few examples:

“Like fire or the sea, he was too simple to be trusted.”
—G.K. Chesterton, in “The Paradise of Thieves”

“No country is so wild and difficult but men will make it a theatre of war. . . .”
—Ambrose Bierce, in “A Horseman in the Sky”

“ ‘Don’t be alarmed,’ said I soothingly. ‘Jenkins, ring the alarm bell. . . .’”
—Pauline E. Hopkins, in “Talma Gordon”

I'll add more from time to time. Meanwhile, please share some from your own notebooks.