Human nature being what it is, they tried to go out the same way they came in ... That was the problem.

There is a great deal of human nature in man.

Subdue your appetites, my dears, and you've conquered human nature.

Shakespeare reveals human nature brilliantly: he shines a light on our instinctive desire to dominate each other.

I tried,

Lincoln was a supreme politician. He understood politics because he understood human nature.