As in geometry the most natural way of beginning is from a mathematical point, so is the same method in observations and natural history the most genuine, simple, and instructive.

"To give is to receive, to love is to be loved, and to live is to let live."

Sometimes we get sad about things and we don’t like to tell other people that we are sad about them. We like to keep it a secret. Or sometimes, we are sad but we really don’t know why we are sad, so we say we aren’t sad but we really are.

The beauty of mathematics is that it is a language that can describe the universe in a way that nothing else can.

The most dangerous phrase in the language is, 'We've always done it this way.'

一个人的孤独不是孤独，一个人找另一个人，一句话找另一句话，才是真正的孤独。