Doubt must be no more than vigilance, otherwise it can become dangerous.

The most dangerous untruths are truths slightly distorted.

If you are going to build something in the air it is always better to build castles than houses of cards.

There is no greater impediment to progress in the sciences than the desire to see it take place too quickly.

The most dangerous untruths are truths moderately distorted.

Man is a masterpiece of creation if for no other reason than that, all the weight of evidence for determinism notwithstanding, he believes he has free will.