Danilo Dolci:

It's important to know that words don't move mountains. Work, exacting work moves mountains.

Edmund Burke:

All that is necessary for evil to succeed is that good men do nothing.

Edward Everett Hale:

I am only one,
But still I am one.
I cannot do everything,
But still I can do something;
And because I cannot do everything
I will not refuse to do the something that I can do.

Franklin D. Roosevelt:

It is common sense to take a method and try it. If it fails, admit it frankly and try another. But above all, try something.