There's no doubt that scientific training helps many authors to write better science fiction. And yet, several of the very best were English majors who could not parse a differential equation to save their lives.
David Brin

Never doubt that you can change history. You already have.
Marge Piercy

At one time I thought the Editor of the Lancet would kindly publish a letter from me on the subject, but further reflection led me to doubt whether so insignificant an individual would be noticed without some special introduction.
William Banting

He was afflicted by the thought that where Beauty was, nothing ever ran quite straight, which no doubt, was why so many people looked on it as immoral.
John Galsworthy

The relationship between commitment and doubt is by no means an antagonistic one. Commitment is healthiest when it's not without doubt but in spite of doubt.
Rollo May

Life is doubt, and faith without doubt is nothing but death.
Miguel de Unamuno

Faith which does not doubt is dead faith.
Miguel de Unamuno

True science teaches, above all, to doubt and to be ignorant.
Miguel de Unamuno

He was thinking alone, and seriously racking his brain to find a direction for this single force four times multiplied, with which he did not doubt, as with the lever for which Archimedes sought, they should succeed in moving the world, when some one tapped gently at his door.
Alexandre Dumas

In the past, it was easier to believe in my own effectiveness. If I worked hard, with good colleagues and good ideas, we could make a difference. But now, I sincerely doubt that.
Margaret J. Wheatley

Ten thousand difficulties do not make one doubt.
John Henry Newman

They who have conquered doubt and fear have conquered failure.
James Allen

When you think you're good, you will play at that level. If you doubt yourself, you will play like crap.
Kurt Russell

A woman will doubt everything you say except it be compliments to herself.
Elbert Hubbard

You go down some street - no doubt it's there, and we have to do something about it, and our programmes are designed to do that - but if that's a picture of Newcastle, it's not the one I recognise and I bet none in the North East do either.
John Prescott

We work n the dark - we do what we can - we give what we have. Our doubt is our passion and our passion is our task. The rest is the madness of art.
Henry James

I doubt that the imagination can be suppressed. If you truly eradicated it in a child, he would grow up to be an eggplant.
Ursula K. Le Guin

Doubt, it seems to me, is the central condition of a human being in the twentieth century.
Salman Rushdie

You will certainly not doubt the necessity of studying astronomy and physics, if you are desirous of comprehending the relation between the world and Providence as it is in reality, and not according to imagination.
Maimonides

Doubt, of whatever kind, can be ended by action alone.
Thomas Carlyle