"Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats."
~Howard Aiken, IBM engineer

"The universe is not only stranger than we think, it is stranger than we can think."
~ Albert Einstein

"Any sufficiently advanced technology is indistinguishable from magic."
~ Arthur C. Clarke

"The  distinction between past, present and future is only an illusion, even if a stubborn one."
~ Albert Einstein

If you think it has merit, you could use "Intellectual courage is at least as rare as the other kind."  ~ S. Thomson 

"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong."
~ R. Buckminster Fuller

"The intuitive mind is a sacred gift, and the rational mind is a faithful servant.  We have created a society which honors the servant, but forgets about the gift."
~ Albert Einstein

"A ship in port is safe, but that is not what ships are for."
~ Rear Admiral Grace Murray Hopper

"What is wanted is not the will to believe, but the will to find out, which is the exact opposite."
~ Bertrand Russell, Skeptical Essays, 1928