What I must do is all that concerns me, not what people think. This rule,equally arduous in actual and intellectual life, may serve for the whole distinction between greatness and meanness. It is the harder, because you will always find those who think they know what is your duty better than you know it. It is easy in the world to live after the world's opinion; it is easy in solitude to live after our own; but the great man is he who in the midst of the crowd keeps with perfect sweetness the independence of solitude.
O but we dreamed to mend Whatever mischief seemed To afflict mankind, but now That winds of winter blow Learn that we were crack-pated when we dreamed.
The greater the scientist, the more he is impressed with his ignorance of reality, and the more he realizes that his laws and labels, descriptions and definitions, are the products of his own thought. They help him to use the world for purposes of his own devising rather than understand and explain it.
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.
Some are born with knowledge, some derive it from study, and some acquire it only after a painful realization of their ignorance. But the knowledge being possessed, it comes to the same thing. Some study with a natural ease, some from a desire for advantages, and some by strenuous effort. But the achievement being made, it comes to the same thing.
Thinking and spoken discourse are the same thing, except that what we call thinking is, precisely, the inward dialogue carried on by the mind with itself without spoken sound.