New insights fail to get put into practice because they conflict with deeply held internal images of how the world works...images that limit us to familiar ways of thinking and acting. That is why the discipline of managing mental models - surfacing, testing, and improving our internal pictures of how the world works - promises to be a major breakthrough for learning organizations.

Books have led some to learning and others to madness.

We say women have made great strides: in biology, in many areas of chemistry, in many places, women are now the majority of medical students. But when I began my career, that wasn't the case. There were very strong stereotypes in biology and medicine.

To teach effectively a teacher must develop a feeling for his subject; he cannot make his students sense its vitality if he does not sense it himself. He cannot share his enthusiasm when he has no enthusiasm to share. How he makes his point may be as important as the point he makes; he must personally feel it to be important.

There are perhaps no days of our childhood we lived so fully as those we spent with a favorite book.

Read. Read every chance you get. Read to keep growing. Read history. Read poetry. Read for pure enjoyment. Read a book called Life on a Little Known Planet. It's about insects. It will make you feel better.