The difference between the insane and the not-insane person is that the latter doesn't do or say the things he thinks.Clarice Lispector
There are too many distractions in this life for quality of thought, and it's quality of thought, not quantity, that counts.Nikola Tesla
It is a far, far better thing to have a firm anchor in nonsense than to put out on the troubled sea of thought.John Kenneth Galbraith
As long as men are free to ask what they will, free to say what they think, free to think what they must, science will never regress and freedom itself will never be wholly lost.J. Robert Oppenheimer
All truly wise thoughts have been thought already thousands of times; but to make them truly ours, we must think them over again honestly, until they take root in our personal experience.Johann Wolfgang von Goethe
A particular train of thought persisted in, be it good or bad, cannot fail to produce its results on the character and circumstances. A man cannot directly choose his circumstances, but he can choose his thoughts, and so indirectly, yet surely, shape his circumstances.James Allen
every man is free to rise as far as he's able or willing, but the degree to which he thinks determines the degree to which he'll rise.Ayn Rand
People demand freedom of speech to make up for the freedom of thought which they avoid.Søren Kierkegaard
Either you think, or else others have to think for you and take power from you, pervert and discipline your natural tastes, civilize and sterilize you.Friedrich Nietzsche
It is just that we should be grateful, not only to those with whose views we may agree, but also to those who have expressed more superficial views; for these also contributed something, by developing before us the powers of thought.Aristotle
As long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost and science can never regress.Marcel Proust
People demand freedom of speech as a compensation for the freedom of thought which they seldom use.Søren Kierkegaard