We have to prepare for what life could become in 40 years. We need to outline what is possible and what is impossible with the non-renewable resources of the Earth. What role will technological improvement play? Taking all this into account, what kind of life can we produce in the best way for 10 billion people? That's a problem that needs to be solved.

Mankind has probably done more damage to the Earth in the 20th century than in all of previous human history.

We know how to organize warfare, but do we know how to act when confronted with peace?

Farming as we do it is hunting, and in the sea we act like barbarians.

I swam across the rocks and compared myself favorably with the sars. To swim fishlike, horizontally, was the logical method in a medium eight hundred times denser than air. To halt and hang attached to nothing, no lines or air pipe to the surface, was a dream. At night I had often had visions of flying by extending my arms as wings. Now I flew without wings. (Since that first aqualung flight, I have never had a dream of flying.)

The sea, once it casts its spell, holds one in its net of wonder forever.

Our society is turning toward more and more needless consumption. It is a vicious circle that I compare to cancer . . . . Should we eliminate suffering, diseases? The idea is beautiful, but perhaps not a benefit for the long term. We should not allow our dread of diseases to endanger the future of our species. . . . In order to stabilize world population, we need to eliminate 350,000 people a day. It is a horrible thing to say, but it's just as bad not to say it.