Thank God men cannot fly, and lay waste the sky as well as the earth.
I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.
It takes two to speak the truth - one to speak, and another to hear.
What is once well done is done forever.
The universe is wider than our views of it.
Men have become the tools of their tools.