Fear is the enemy of logic.

Logic is a poor guide compared with custom.

For nothing is more democratic than logic; it is no respecter of persons and makes no distinction between crooked and straight noses.

The extraordinary courage and wisdom of Kant and Schopenhauer have succeeded in gaining the most difficult victory, the victory over the optimism concealed in the essence of logic-an optimism that is the basis of our culture.

For a lot of companies, it's useful for them to feel like they have an obvious competitor and to rally around that. I personally believe it's better to shoot higher. You don't want to be looking at your competitors. You want to be looking at what's possible and how to make the world better.

Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense.