If we are ever in doubt about what to do, it is a good rule to ask ourselves what we shall wish on the morrow that we had done.

Doubt yourself and you doubt everything you see. Judge yourself and you see judges everywhere. But if you listen to the sound of your own voice, you can rise above doubt and judgment. And you can see forever.

There is no doubt that we should take solar radiation into account. We have seen ground temperatures rising since 1975, and it is important to know to what extent that has been caused by the sun or by carbon dioxide.

It is better to remain silent and be thought a fool than to open one's mouth and remove all doubt.

I know that we're being inexorably taken over by the Americans. Without a doubt. I don't mean invaded or anything like that, just taken over. By degrees.

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

In these times, the hardest task for social or political activists is to find a way to get people to wonder again about what we all believe is true. The challenge is to sow doubt.

Power runs with ideas that only the crazy would draw into doubt.

Whenever man begins to doubt himself, he does something so stupid that he is reassured.

Melancholy and sadness are the start of doubt... doubt is the beginning of despair; despair is the cruel beginning of the differing degrees of wickedness.

There is no doubt that I, also, had long been aware of the problem, i.e. producing X-ray interferences, before the inherent difficulties had finally been surmounted.

God has stated in clear and concise language how He created the universe and we ought not to doubt His Word.

Indeed, I am sometimes inclined to doubt whether some men consider youth as rational and intelligent beings, with minds capable of expansion, and talents formed for usefulness.

However, I don't doubt that a wave of immigration will come to Poland.

There are two ways to slice easily thorugh life; to believe everything or to doubt everything. Both ways save us from thinking.