The learning and knowledge that we have, is, at the most, but little compared with that of which we are ignorant.

Those who don't know must learn from those who do.

Knowledge which is acquired under compulsion obtains no hold on the mind.

Either we shall find what it is we are seeking or at least we shall free ourselves from the persuasion that we know what we do not know.

To appreciate the beauty of a snow flake, it is necessary to stand out in the cold.

To suffer the penalty of too much haste, which is too little speed.