You don't really understand human nature unless you know why a child on a merry-go-round will wave at his parents every time around - and why his parents will always wave back.

His works (taken together) are almost like a new edition of human nature.

In the general course of human nature, A power over a man's subsistence amounts to a power over his will.

If the Martians can translate this and interpret it, it will give them an interesting view of human nature.

Something in human nature causes us to start slacking off at our moment of greatest accomplishment. As you become successful, you will need a great deal of self-discipline not to lose your sense of balance, humility, and commitment.

It's human nature to expect that the people that will respond early and faster will be the people that will more than likely be coming back. And we recognize that we haven't reached everyone but we reached enough people that we feel like the numbers are valid.