In science it often happens that scientists say, ‘You know that’s a really good argument; my position is mistaken,’ and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn’t happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
~ Carl Sagan
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Self-possession implies the capacity for self-restraint, self-compulsion and self-direction; and he who has these, if he live long enough, can have any other possession that he wants.
~ William Hanna Thompson
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The surface area of Mars is exactly as large as the land area of the Earth. A thorough reconnaissance will clearly occupy us for centuries. But there will be a time when Mars is all explored; a time after robot aircraft have mapped it from aloft, a time after rovers have combed the surface, a time after samples have been returned safely to Earth, a time after human beings have walked the sands of Mars. What then? What shall we do with Mars?
~ Carl Sagan
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You gain strength, courage and confidence by every experience in which you really stop to look fear in the face. You are able to say to yourself, “I have lived through this horror. I can take the next thing that comes along.” … You must do the thing you think you cannot do.
~ Eleanor Roosevelt
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