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.

Personal mastery teaches us to choose. Choosing is a courageous act: picking the results and actions which you will make into your destiny.

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

Consider prejudice. Once a person begins to accept a stereotype of a particular group, that "thought" becomes an active agent, "participating" in shaping how he or she interacts with another person who falls in that stereotyped class. In turn, the tone of their interaction influences the other person's behaviour. The prejudiced person can't see how his prejudice shapes what he "sees" and how he acts. In some sense, if he did, he would no longer be prejudiced. To operate, the "thought" of prejudice must remain hidden to its holder

I often say that leadership is deeply personal and inherently collective. That's a paradox that effective leaders have to embrace.

Structures of which we are unaware hold us prisoner.

People with high levels of personal mastery...cannot afford to choose between reason and intuition, or head and heart, any more than they would choose to walk on one leg or see with one eye.