We learn together in teams. This involves a shift from a spirit of advocacy to a spirit of enquiry.

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.

People with a high level of personal mastery are able to consistently realize the results that matter most deeply to them-in effect, they approach their life as an artist would approach a work of art. The do that by becoming committed to their own lifelong learning.

Small changes can produce big results - but the areas of highest leverage are often the least obvious.

In a learning organization, leaders are designers, stewards, and teachers. They are responsible for building organizations where people continually expand their capabilities to understand complexity, clarify vision, and improve shared mental models - that is, they are responsible for learning.

When teams are truly learning, not only are they producing extraordinary results, but the individual members are growing more rapidly than could have occurred otherwise.

Mental models are deeply ingrained assumptions, generalizations, or even pictures of images that influence how we understand the world and how we take action.