Everyone is perfectly willing to learn from unpleasant experience - if only the damage of the first lesson could be repaired.

Delicacy in woman is strength.

Doubt must be no more than vigilance, otherwise it can become dangerous.

Even truth needs to be clad in new garments if it is to appeal to a new age.

Do not say hypothesis, and even less theory: say way of thinking.

The natural scientists of the previous age knew less than we do and believed they were very close to the goal: we have taken very great steps in its direction and now discover we are still very far away from it. With the most rational philosophers an increase in their knowledge is always attended by an increased conviction of their ignorance.

The most entertaining surface on earth is the human face.