"It seems to me that the natural world is the greatest source of excitement the greatest source of visual beauty the greatest source of intellectual interest. It is the greatest source of so much in life that makes life worth living."

"I can mention many moments that were unforgettable and revelatory. But the most single revelatory three minutes was the first time I put on scuba gear and dived on a coral reef. It's just the unbelievable fact that you can move in three dimensions."

"It's coming home to roost over the next 50 years or so. It's not just climate change it's sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now."

"People must feel that the natural world is important and valuable and beautiful and wonderful and an amazement and a pleasure."

"Today's date, the eighteenth of May, should sometime become an occasion of great international celebration, for on this day ten years ago the first Peace Conference opened at The Hague."

"Political liberty, the peace of a nation, and science itself are gifts for which Fate demands a heavy tax in blood!"

"War had always seemed to me to be a purely human behavior. Accounts of warlike behavior date back to the very first written records of human history it seemed to be an almost universal characteristic of human groups."

"A peace deal requires agreements, and you don't make agreements with your friends, you make agreements with your enemies."