Conscious processing systems within the large sheet of cortex folded above and around our brainstem allow us to get beyond innate to intelligent responses when confronting complex challenges. The cortex is divided into quadrants — the sensory and frontal lobes, and the right and left hemispheres. The sensory lobes at the back identify the nature and dynamics of a challenge, and the frontal lobes develop an appropriate response.

The purpose of the two highly interconnected hemispheres has long been an enigma, but Goldberg's intriguing analysis of their distinctive functions explains many mysteries from creativity to the arts to institutional policies to wisdom—and it poses serious challenges to educators.

Goldberg suggests that the fundamental organizing principle for the right and left hemispheres emerges out of an important question a brain must ask whenever danger or opportunity looms: Have I confronted this challenge before?

He provides considerable research evidence to argue that the right hemisphere (in most humans) is organized principally to process novel challenges, and the left hemisphere familiar routines. For example we process strange faces principally in our right hemisphere, and familiar faces in the left. Musically naïve people process music principally in their right hemisphere, trained musicians in the left.

Goldberg argues that although both hemispheres are active in processing most cognitive functions, the relative level of involvement shifts from the right to the left hemisphere over time, and with increased familiarity and competence. The exploratory right hemisphere is thus organized to rapidly and creatively respond to a novel challenge, but the more stable processing systems in the left hemisphere eventually transform the successful initial responses into an efficient established routine that we activate whenever the challenge (or something close to it) reoccurs.