It is not enough to have a good...

It is not enough to have a good mind; the main thing is to use it well.

--Rene Descartes

See this quotation on Prometheus Unplugged.

Dubito ergo cogito...

Dubito ergo cogito; cogito ergo sum.
(I doubt, therefore I think; I think therefore I am.)

--Rene Descartes

Nietzsche and Modern Times; A Study of Bacon, Descartes, and Nietzsche

The significant problems we have...

The significant problems we have cannot be solved at the same level of thinking with which we created them.

--Albert Einstein

Bite-Size Einstein: Quotations On Just About Everything From The Greatest Mind Of The Twentieth Century (Hardcover)

I never think of the future...

I never think of the future - it comes soon enough.

--Albert Einstein

Bite-Size Einstein: Quotations On Just About Everything From The Greatest Mind Of The Twentieth Century (Hardcover)

Under conditions of tyranny...

Under conditions of tyranny it is far easier to act than to think.

--Hannah Arendt

Think like a man of action...

Think like a man of action, act like a man of thought.

--Henri Bergson

I reject "get it done," " make it happen" thinking...

I reject "get it done," "make it happen" thinking. I want to slow things down so I understand them better.

--Jerry Brown (Governor)

I can give you a six-word formula...

I can give you a six-word formula for success: "Think things through - then follow through."

-- Edward Rickenbacker

He is able who...

He is able who thinks he is able.

--Buddha