Without doubt, machinery has greatly increased the number of well-to-do idlers.
Karl Marx

Doubt grows with knowledge.
Johann Wolfgang von Goethe

We know accurately only when we know little, with knowledge doubt increases.
Johann Wolfgang von Goethe

Beyond a doubt truth bears the same relation to falsehood as light to darkness.
Leonardo da Vinci

Who shall decide when doctors disagree, And soundest casuists doubt, like you and me?
Alexander Pope

How prone to doubt, how cautious are the wise!
Alexander Pope

No doubt exists that all women are crazy; it's only a question of degree.
W. C. Fields

I, with a deeper instinct, choose a man who compels my strength, who makes enormous demands on me, who does not doubt my courage or my toughness, who does not believe me naive or innocent, who has the courage to treat me like a woman.
Anais Nin

It is beyond a doubt that all our knowledge that begins with experience.
Immanuel Kant

If the Sun and Moon should ever doubt, they'd immediately go out.
William Blake

I no doubt deserved my enemies, but I don't believe I deserved my friends.
Walt Whitman

There can be no doubt that the average man blames much more than he praises. His instinct is to blame. If he is satisfied he says nothing; if he is not, he most illogically kicks up a row.
Golda Meir

I love to doubt as well as know.
Dante Alighieri

A conservative is someone who makes no changes and consults his grandmother when in doubt.
Woodrow Wilson

And I have no doubt that every new example will succeed, as every past one has done, in showing that religion and Government will both exist in greater purity, the less they are mixed together.
James Madison

I have no doubt but that the misery of the lower classes will be found to abate whenever the Government assumes a freer aspect and the laws favor a subdivision of Property.
James Madison

I find that the best way to do things is to constantly move forward and to never doubt anything and keep moving forward, if you make a mistake say you made a mistake.
John Frusciante

Should I perchance still feel after my death, I would no longer have any doubt, but I would most certainly give the lie to anyone asserting before me that I was dead.
Giacomo Casanova

There is too much fathering going on just now and there is no doubt about it fathers are depressing.
Gertrude Stein

Great leaders are almost always great simplifiers, who can cut through argument, debate and doubt, to offer a solution everybody can understand.
Colin Powell