A statement is persuasive and credible either because it is directly self-evident or because it appears to be proved from other statements that are so.

When I get logical, and I don’t trust my instincts – that’s when I get in trouble.

The great proof of madness is the disproportion of one’s designs to one’s means.

Perhaps, as some wit remarked, the best proof that there is Intelligent Life in Outer Space is the fact it hasn’t come here. Well, it can’t hide forever – one day we will overhear it.

I am not a crook.

There’s no doubt that inequality destabilizes societies. I think the social science evidence on that front is crystal clear.

A bookstore is one of the only pieces of evidence we have that people are still thinking.

A masterpiece is something said once and for all, stated, finished, so that it’s there complete in the mind, if only at the back.

The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd.

We are certainly not to relinquish the evidence of experiments for the sake of dreams and vain fictions of our own devising; nor are we to recede from the analogy of Nature, which is wont to be simple and always consonant to itself.

One cannot really argue with a mathematical theorem.

Truth is by nature self-evident. As soon as you remove the cobwebs of ignorance that surround it, it shines clear.

Faith is different from proof; the latter is human, the former is a Gift from God.

Facts are stubborn things.

The fact that a man is a newspaper reporter is evidence of some flaw of character.

We must accept what science tells us, that man was born from the earth. But, more logical than the scientists who lecture us, we must carry this lesson to its conclusion: that is to say, accept that man was born entirely from the world – not only his flesh and bones but his incredible power of thought.

Where the senses fail us, reason must step in.

Several excuses are always less convincing than one.

I might talk about killing people, but that doesn’t mean I do it.

Whatsoever is contrary to nature is contrary to reason, and whatsoever is contrary to reason is absurd.

The most savage controversies are about matters as to which there is no good evidence either way.

What convinces is conviction. Believe in the argument you’re advancing. If you don’t you’re as good as dead. The other person will sense that something isn’t there, and no chain of reasoning, no matter how logical or elegant or brilliant, will win your case for you.

All credibility, all good conscience, all evidence of truth come only from the senses.

Fashion is made to become unfashionable.

Power is not sufficient evidence of truth.

Resort is had to ridicule only when reason is against us.

Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.

It has been said that man is a rational animal. All my life I have been searching for evidence which could support this.

Cooking today is a young man’s game, I don’t give a bollocks what anyone says.

The progress of evolution from President Washington to President Grant was alone evidence to upset Darwin.

No sadder proof can be given by a man of his own littleness than disbelief in great men.

Don’t think you are going to conceal thoughts by concealing evidence that they ever existed.

The highest proof of the spirit is love. Love the eternal thing which can already on earth possess as it really is.

There is no logical way to the discovery of these elemental laws. There is only the way of intuition, which is helped by a feeling for the order lying behind the appearance.

In the absence of any other proof, the thumb alone would convince me of God’s existence.

Dr. Karel Culik is an outstanding applied mathematician, a specialist in algebra, logic, computer sciences and mathematical linguistics. In 1965, he visited the linguistics research program at MIT, and we have worked together on several projects since.

What can be asserted without evidence can be dismissed without evidence.

It is surely harmful to souls to make it a heresy to believe what is proved.

I call him free who is led solely by reason.

I don’t believe it. Prove it to me and I still won’t believe it.

Nature is the source of all true knowledge. She has her own logic, her own laws, she has no effect without cause nor invention without necessity.

I’ll assure you this: I will have nothing to do with politics.

I’m the proof – you can’t throw away tradition.

It’s not bragging if you can back it up.

Contradiction is not a sign of falsity, nor the lack of contradiction a sign of truth.

Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and the relativity ideas are examples of this.

The word ‚racism‘ is like ketchup. It can be put on practically anything – and demanding evidence makes you a ‚racist.‘

It has yet to be proven that intelligence has any survival value.

Absence of evidence is not evidence of absence.

I am not part of the problem. I am a Republican.

Don’t join the book burners. Do not think you are going to conceal thoughts by concealing evidence that they ever existed.

Logic will get you from A to B. Imagination will take you everywhere.

With impressive proof on all sides of magnificent progress, no one can rightly deny the fundamental correctness of our economic system.

Faith is a knowledge within the heart, beyond the reach of proof.

I entered the health care debate in response to a statement in the United States press in summer 2009 which claimed the National Health Service in Great Britain would have killed me off, were I a British citizen. I felt compelled to make a statement to explain the error.

I like mathematics because it is not human and has nothing particular to do with this planet or with the whole accidental universe – because, like Spinoza’s God, it won’t love us in return.

What can you do against the lunatic who is more intelligent than yourself, who gives your arguments a fair hearing and then simply persists in his lunacy?

Well, we can’t say any more than we can say there is no god, there is no afterlife. We can only say there is no persuasive evidence for or argument for it.

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

In argument similes are like songs in love; they describe much, but prove nothing.

No amount of experimentation can ever prove me right; a single experiment can prove me wrong.