How to win friends and influence people
"Don't complain about the snow on your neighbor's roof when your own doorstep is unclean"
This chapter revolves around criticism. The author describes criticism as futile, as it puts people on the defensive and usually makes them strive to justify themselves. It wounds their pride, hurts their sense of importance, and arouses resentment.
Criticizing others means to incur resentment. He brings up Abraham Lincoln and Benjamin Franklin who went from criticizing to becoming very diplomatic.
Instead of condemning people, try to figure out why they do what they do and show empathism. Also look at yourself, and try to improve your own flaws first.