My younger brother, Ryan, is a wonderful man. He has worked as a paramedic in Atlanta, Georgia, for more than twenty-five years. His lengthy service has refined his ability to assess perilous situations and determine effective ways to respond. Ryan has developed these skills through vigilance and repetition, which have made his actions nearly automatic. Whether a person is shot, stabbed, or hit by a vehicle, Ryan possesses the skills to act in life-saving ways with confidence and immediacy.

Ryan is also a fount of knowledge regarding his profession. He has studied and practiced his craft with enough discipline to identify the truth in crisis situations quickly and accurately. He knows how to diagnose life-threatening ailments and how to use the medical tools at his disposal to aid his patients.

In addition to his skill and knowledge, there is something more. Ryan’s presence, all six feet, two inches and three hundred pounds of it, is reassuring and comforting. Despite his imposing stature, he is kind, patient, and gentle. People are likely to feel safer and calmer by the mere look on his countenance. If an accident or illness befalls you in Atlanta, heaven forbid, you want my brother to be the one to help.

Researchers and scholars who study expertise typically write about the subject as a combination of skill and knowledge. In recent years, however, researchers, like Gloria Dall’Alba, a professor at the University of Queensland in Australia, have been looking more closely at the third ingredient: attitude. Dall’Alba has observed that expertise appears to “incorporate not only high levels of knowledge and skills, but also something else besides.” She concludes that expertise is a combination of knowledge, skill, and an “embodied being in the world, inescapably entwined with others and things.”

Developing expertise must include ways of performing tasks with proficiency and skill. It also includes mastering the subject and knowing the truths that govern the domain. And, finally, expertise is a form of being. It is the manner of interaction between oneself and the world. It is the edge of contact. It is the way Ryan interacts with patients, beyond his skill and his knowledge.

In short, scholars point to three dimensions that make up an expert. Similarly, so do my professional observations. Expertise is the skillful way of doing things, the truth that governs its domain, and the life that draws people to it.