Be gentle to all and stern with yourself.
Things do not happen. Things are made to happen.
If you've got a talent, protect it.
The wise does at once what the fool does at last.
Leap, and the net will appear.
I can, therefore I am.
Expect problems and eat them for breakfast.
Know or listen to those who know.
Do not weep do not wax indignant. Understand.
It's always too early to quit.
In those early years in New York when I was a stranger in a big city, it was the companionship and later friendship which I was offered in the Linnean Society that was the most important thing in my life.