„Teach thy tongue to say, “I do not know,” and thous shalt progress.”

The measure of intelligence is the ability to change.

Measure not the work until the day's out and the labor done.

The greater part of human pain is unnecessary. It is self-created as long as the unobserved mind runs your life

We are all in the gutter, but some of us are looking at the stars.

The free exploring mind of the individual human is the most valuable thing.

Thinking is difficult, that's why most people judge.