"Out of the crooked timber of humanity, no straight thing was ever made." So says Immanuel Kant. And it is found in Idea for a General History with a Cosmopolitan Purpose (1784), Proposition 6.
References for quotes are some of my favorite things to see. It helps me think someone is doing their little bit of work to bring order to the internet. Quote by quote.
"Pro tip: even if you don't use the reference in your poster or post, at least verify the accuracy in your research. It'll make the world just a little bit better." —Thomas Jefferson