Do not worry about your difficulties in mathematics. I can assure you mine are still greater.

A man should look for what is, and not for what he thinks should be.

Few are those who see with their own eyes and feel with their own hearts

Once we accept our limits, we go beyond them.

Everyone should be respected as an individual, but no one idolized.

The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it

It has become appallingly obvious that our technology has exceeded our humanity.

To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.

We cannot solve our problems with the same thinking we used when we created them.

Look deep into nature, and then you will understand everything better.