This document discusses three great minds and their perspectives on what makes humans unique: Richard Leakey, Carl Sagan, and B.F. Skinner. It summarizes their views that human intelligence, nurtured through a long childhood and shaped by culture and environment, is what has allowed humanity to survive and is our best hope for overcoming future challenges. Sagan believed our intelligence is rare in the universe and contact with other intelligent life may be possible through radio telescopes. Skinner's design for the community of Walden Two showed how culture could maximize nurture. Overall, the document argues that human intelligence, rather than just genes, is key to survival when the world is changing rapidly.