To dwell on the things that depress or anger us does not help in overcoming them. One must knock them down alone.

Live with purpose. Don't let people or things around you get you down.

Only the one who does not question is safe from making a mistake.

Thinking is to man what flying is to birds. Don’t follow the example of a chicken when you could be a lark.

I believe that the first step in the setting of a real external world is the formation of the concept of bodily objects and of bodily objects of various kinds.

The most valuable thing a teacher can impart to children is not knowledge and understanding per se but a longing for knowledge and understanding, and an appreciation for intellectual values, whether they be artistic, scientific, or moral. It is the supreme art of the teacher to awaken joy in creative expression and knowledge. Most teachers waste their time by asking questions that are intended to discover what a pupil does not know, whereas the true art of questioning is to discover what the pupil does know or is capable of knowing.

The Nuremberg Trial of the German war criminals was tacitly based on the recognition of the principle: criminal actions cannot be excused if committed on government orders; conscience supersedes the authority of the law of the state.