It was difficult to hold Broca's brain without wondering whether in some sense Broca was still <i>in</i> there — his wit, his skeptical mien, his abr… - Carl Sagan

I have not the qualifications for teaching my philosophy of life. I have barely qualifications for practicing the philosophy I believe. I am but a poor struggling soul yearning to be … wholly truthful and wholly nonviolent in thought, word and deed, but ever failing to reach the ideal.

Our perceptions may be distorted by training and prejudice or merely because of the limitations of our sense organs, which, of course, perceive directly but a small fraction of the phenomena of the world. Even so straightforward a question as whether in the absence of friction a pound of lead falls faster than a gram of fluff was answered incorrectly by Aristotle and almost everyone else before the time of Galileo. Science is based on experiment, on a willingness to challenge old dogma, on an openness to see the universe as it really is. Accordingly, science sometimes requires courage—at the very least the courage to question the conventional wisdom.

Imagination will often carry us to worlds that never were, but without it we go nowhere.