There is no counting the unsolved problems of Natural History.

The most powerful factors in the world are clear ideas in the minds of energetic men of good will.

The man who has grit enough to bring about the afforestation or the irrigation of a country is not less worthy of honor than its conqueror.

The chief end of science is to make things clear, the educative aim is to foster the inquisitive spirit.

Was it not the great philosopher and mathematician Leibnitz who said that the more knowledge advances the more it becomes possible to condense it into little books?

The Doctrine of Evolution states the fact that the present is the child of the past and the parent of the future.

A prolonged war in which a nation takes part is bound to impoverish the breed, since the character of the breed depends on the men who are left.

Scars are the awards of success, not the medals.

Where must we go, we who wander this wasteland, in search of our better selves.

A person's got to think, otherwise that person's no better than a trained seal balancing a ball on his nose. If only that seal could think, he'd know he was making a thousand children laugh.

It's easier to limit yourself, but if you do, you will never reach your true potential.

Life can only be as new as you Choose to be.

Flattery has to overcome my mistrust, and it does.

Empowerment of individuals and communities is absolutely central. Getting the community involved in organising their own destiny has got to be a key part of it.

Some things just won’t go away, no matter how hard you scrub.

One can't live on love alone; and I am so stupid that I can do nothing but think of him.

All I know is that my best work has come out of being committed and happy.