1. “We need to teach how doubt is not to be feared but welcomed. It’s OK to say, “I don’t know.””

— Richard P. Feynman

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2. “I appear as a skeptic, who believes that doubt is the great engine, the great fuel of all inquiry, all discovery and all innovation.”

— Christopher Hitchens

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3. “The first principle is that you must not fool yourself and you are the easiest person to fool.”

— Richard P. Feynman

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4. “The worst enemy to creativity is self-doubt.”

— Sylvia Plath

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5. “Banish doubt. When doubt is banished, abundance flourishes and anything is possible.”

— Wayne W. Dyer

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6. “There is nothing more dreadful than the habit of doubt. Doubt separates people. It is a poison that disintegrates friendships and breaks up pleasant relations. It is a thorn that irritates and hurts; it is a sword that kills.”

— Buddha

Also Featured in: Mindset Quotes, Buddhist Quotes

7. “Religion is a culture of faith; science is a culture of doubt.”

— Richard P. Feynman

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8. “Doubt is the origin of wisdom.”

— René Descartes

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9. “People are afraid to pursue their most important dreams, because they feel that they don’t deserve them, or that they’ll be unable to achieve them.”

— Paulo Coelho

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10. “When we got Tesla going at the very beginning, if you asked me what I thought the odds of success were, I would have said less than 50%. I would have said that failure is the most likely outcome.”

— Elon Musk

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11. “I would never die for my beliefs because I might be wrong.”

— Bertrand Russell

Also Featured in: Philosophy Quotes, Fear Quotes

12. “Tell people there’s an invisible man in the sky who created the universe, and the vast majority will believe you. Tell them the paint is wet, and they have to touch it to be sure.”

— George Carlin

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13. “Doubt is not a pleasant condition, but certainty is absurd.”

— Voltaire

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14. “Doubt can only be removed by action.”

— Johann Wolfgang von Goethe

Also Featured in: Quotes About Acting

15. “Have faith in your skills, negative thoughts kill. Self-doubt will kill your dreams before others do. Doubt kills more dreams than failure ever will.”

— Suzy Kassem

Also Featured in: Dream Big Quotes, Overcoming Fear Quotes, Being Strong Quotes, Graduation Quotes, Quotes About Skills

16. “If you think you are beaten, you are. If you think you dare not, you don’t. If you’d like to win, but you think you can’t, it is almost a cinch that you won’t.”

— Walter D. Wintle

Also Featured in: Perspective Quotes, Winning Quotes, Giving Up Quotes, Expectations Quotes, Path Quotes

17. “Religion is poison because it asks us to give up our most precious faculty, which is that of reason, and to believe things without evidence. It then asks us to respect this, which it calls faith.”

— Christopher Hitchens

Also Featured in: Truth Quotes

18. “Don’t let anyone tell you you can’t do something, because you can!”

— Greg Plitt

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19. “Any truth is better than indefinite doubt.”

— Arthur Conan Doyle

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20. “Fear and self-doubt have always been the greatest enemies of human potential.”

— Brian Tracy

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21. “When in doubt, just take the next small step.”

— Paulo Coelho

22. “Don’t ever let someone tell you that you can’t do something.”

— Chris Gardner

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23. “I release all fears and doubts. I accept myself and create peace in my mind and heart. I now choose to free myself from all destructive fears and doubts. I am loved and I am safe.”

— Louise Hay

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24. “I’m not okay.”

— Gerard Way

Also Featured in: Sorrow Quotes, Depression Quotes, Loneliness Quotes, Honesty Quotes

25. “One thing I know, that I know nothing. This is the source of my wisdom.”

— Socrates

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26. “Human decency is not derived from religion. It precedes it.”

— Christopher Hitchens

Also Featured in: Human Nature Quotes, Hard Hitting Quotes, Humanism Quotes

27. “If you are insecure, guess what? The rest of the world is too. Do not overestimate the competition and underestimate yourself. You are better than you think.”

— T. Harv Eker

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28. “In all affairs it’s a healthy thing now and then to hang a question mark on the things you have long taken for granted.”

— Bertrand Russell

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29. “I don’t care if the whole world is against you or teasing you or saying you are not gonna make it. Believe in yourself, no matter what.”

— Michael Jackson

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30. “The deepest sin against the human mind is to believe things without evidence.”

— Aldous Huxley

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31. “I know nothing except the fact of my ignorance.”

— Socrates

Also Featured in: Truth Quotes, Intelligence Quotes, Humility Quotes

32. “Is this what I want to be? This? Is this all I’ve got – is this everything I can give? Is this going to be my life? Do I accept that?”

— Jocko Willink

33. “I love it when people doubt me. It makes me work harder to prove them wrong.”

— Derek Jeter

34. “The moment you doubt whether you can fly, you cease for ever to be able to do it.”

— J.M. Barrie

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35. “We want to have certainties and no doubts – results and no experiments – without even seeing that certainties can arise only through doubt and results only through experiment.”

— C.G. Jung

36. “Start now. Start where you are. Start with fear. Start with pain. Start with doubt. Start with hands shaking. Start with voice trembling but start. Start and don’t stop. Start where you are, with what you have. Just... start.”

— Ijeoma Umebinyuo

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37. “I may be wrong and you may be right, and by an effort, we may get nearer to the truth.”

— Karl Popper

38. “I promise to question everything my leaders tell me. I promise to use my critical faculties. I promise to develop my independence of thought. I promise to educate myself so I can make my own judgments.”

— Carl Sagan

Also Featured in: Lifelong Learning Quotes, Quotes About Thinking, Inspirational Quotes for Students

39. “I’m a creep. I’m a weirdo. What the hell am I doing here? I don’t belong here.”

— Thom Yorke

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40. “I have no time to waste on this planet being told what to do by those who think that God has given them instructions.”

— Christopher Hitchens

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41. “Once I dreamed I was a butterfly, and now I no longer know whether I am Chuang Tzu, who dreamed I was a butterfly, or whether I am a butterfly dreaming that I am Chuang Tzu.”

— Zhuangzi

Also Featured in: Crazy Quotes, Taoism Quotes, Quotes About Reality

42. “Doubt isn’t the opposite of faith; it is an element of faith.”

— Paul Tillich

43. “But I could be wrong.”

— Carl Sagan

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44. “I was feeling insecure you might not love me anymore.”

— John Lennon

Also Featured in: Romantic Quotes, Love Hurts Quotes

45. “I hate you, God. I hate you as though you actually exist.”

— Graham Greene

46. “If you must doubt something, doubt your limits.”

— Price Pritchett

47. “Either God can do nothing to stop catastrophes like this, or he doesn’t care to, or he doesn’t exist. God is either impotent, evil, or imaginary. Take your pick, and choose wisely.”

— Sam Harris

48. “My first rule: I don’t believe anything the government tells me.”

— George Carlin

Also Featured in: Hilarious Quotes, Firsts Quotes, Government Quotes

49. “I’m an atheist. I’m not neutral about religion, I’m hostile to it. I think it is a positively bad idea, not just a false one. And I mean not just organized religion, but religious belief itself.”

— Christopher Hitchens

Also Featured in: Rejection Quotes

50. “I don't want to believe. I want to know.”

— Carl Sagan

Also Featured in: Science Quotes, Universe Quotes, Knowledge Quotes, Truth Quotes