We learn the social norms of our society and modify our behaviour accordingly.

Someday we shall look back on this dark era of agriculture and shake our heads. How could we have ever believed that it was a good idea to grow our food with poisons?

The best relationship you can have with a chimpanzee is total mutual trust.

The tree I had in the garden as a child, my beech tree, I used to climb up there and spend hours. I took my homework up there, my books, I went up there if I was sad, and it just felt very good to be up there among the green leaves and the birds and the sky.

We can't leave people in abject poverty, so we need to raise the standard of living for 80% of the world's people, while bringing it down considerably for the 20% who are destroying our natural resources.

I would never say I was an icon, but so many people have said I am, so I suppose I am. I mean, I can't not be what everyone says I am. But I don't feel like an icon.

You can't do everything. You can't do health and forestry and agriculture. You've got to focus and do one or the other.