Good quotes are like good poems, they can say a lot--often of great significance, in a few words. Here are some of my favorites:

Knowledge has to be acquired by hard work; none of it is flung at our heads gratis. (Mark Twain)

We have evolved to be curious, and science has revealed that if we just look, there is magic everywhere. (Ronald Pine)
Men are, in the mass, still emotional and resistant to fact. (Loren Eiseley)

There must be no imagining or supposing, but simply discovering what nature does or undergoes.
     (Francis Bacon)

Bad it is when a man eats his fill all day, and has nought to task the mind. (Confucius)

All beings alive today are equally evolved. All have survived over three thousand million years of evolution from common bacterial ancestors. (Lynn Margulis)

- - study without desire ruins the memory and results in the retention of nothing that is apprehended.
           (Leonardo da Vinci)
The main discovery during this century of research and science has probably been the depth of our
ignorance on nature. The more we learn, the more we realize the extent of our ignorance.
           (Francois Jacob)
Genes that cause individuals to maximize their descendants are the genes we expect to see in the world.
          (Richard Dawkins)
I cannot admit any method of arriving at truth except that of science. --and--
One should always keep an open mind, but not so open that one’s brains fall out. (Bertrand Russell )
The mind is its own place, and itself can make a heaven of hell, a hell of heaven. (John Milton)
The more the universe seems comprehensible, the more it also seems pointless. (Steven Weinberg)

The scientific view of the external world must reside at the core of the examined life.
     ( Jonathan Singer)

Nothing is great but the inexhaustible wealth of nature. She shows us only surfaces, but she is a
           million fathoms deep. (Ralph Waldo Emerson)
Humankind cannot bear very much reality.    (T.S. Eliot)