Take nothing but pictures.
Leave nothing but footprints.
Kill nothing but time.

Motto of the Baltimore Grotto, a caving society

Till now man has been up against Nature; from now on he will be up against his own nature. 

Dennis Gabor, Inventing the Future, 1963

A living planet is a much more complex metaphor for deity than just a bigger father with a bigger fist.  If an omniscient, all-powerful Dad ignores your prayers, it’s taken personally.  Hear only silence long enough, and you start wondering about his power.  His fairness.  His very existence.  But if a world mother doesn’t reply, Her excuse is simple.  She never claimed conceited omnipotence.  She has countless others clinging to her apron strings, including myriad species unable to speak for themselves.  To Her elder offspring She says – go raid the fridge.  Go play outside.  Go get a job.  Or, better yet, lend me a hand.  I have no time for idle whining. 

David Brin

It is better to weep with wise men than to laugh with fools. 

Spanish Proverb

Suppose the world were only one of God’s jokes, would you work any the less to make it a good joke instead of a bad one?

George Bernard Shaw

I would feel more optimistic about a bright future for man if he spent less time proving that he can outwit Nature and more time tasting her sweetness and respecting her seniority. 

Elwyn Brooks White, Essays of E.B. White, 1977

I only went out for a walk and finally concluded to stay out till sundown, for going out, I found, was really going in. 

John Muir, 1913, in L.M. Wolfe, ed., John Muir, John of the Mountains:  The Unpublished Journals of John Muir, 1938

For 200 years we’ve been conquering Nature.  Now we’re beating it to death. 

Tom McMillan, quoted in Francesca Lyman, The Greenhouse Trap, 1990

Every day is Earth Day.  

Author Unknown

I conceive that the land belongs to a vast family of which many are dead, few are living, and countless numbers are still unborn.  

A Chieftan from Nigeria