Don't be content to be the chip off the old block - be the old block itself.

A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty.

All dogs look up to you. All cats look down on you. Only the pig looks at you as an equal

If you mean to profit, learn to please.

If, however, there is to be a war of nerves let us make sure our nerves are strong and are fortified by the deepest convictions of our hearts.

Keep calm and carry on.

Science has given to this generation the means of unlimited disaster or of unlimited progress. There will remain the greater task of directing knowledge lastingly towards the purpose of peace and human good.