The only path by which another person can upset you is through your own thought.

Losers live in the past. Winners learn from the past and enjoy working in the present toward the future.

Logic will get you from A to Z, imagination will get you everywhere.

The more I see, the less I know for sure.

Thinking is the talking of the soul with itself.

Happiness is just how you feel when you don't feel miserable.

A man is but the product of his thoughts. What he thinks he becomes.

I'm not afraid of death because I don't believe in it.

The highest possible stage in moral culture is when we recognise that we ought to control our thoughts.