Mankind's greatest achievements have come about by talking and its greatest failures by not talking. It doesn’t have to be like this.

Every man should marry. After all, happiness is not the only thing in life.

It was recently discovered that research causes cancer in rats.

I don't think the human race will survive the next thousand years, unless we spread into space. There are too many accidents that can befall life on a single planet. But I'm an optimist. We will reach out to the stars.

No one can resist the idea of a crippled genius.

Plagiarism saves time.

I think [contacting an alien civilization] would be a disaster. The extraterrestrials would probably be far in advance of us. The history of advanced races meeting more primitive people on this planet is not very happy, and they were the same species. I think we should keep our heads low.