The chapter begins by illustrating what doctors were like in the mid-1800s. They looked like upper-class men, their clothing formal and elegant. Surgery was a developing art form. Doctors had just begun using ether anesthesia to perform surgeries. Ether allowed them to remove flesh and bone without causing the patient too much pain. However, doctors knew nothing about germs, bacteria, or how the brain worked. Doctors didn’t use gloves or masks during procedures, and most didn’t wash their hands before operating.

Once Gage arrived in Boston, he became both a patient and an object of curiosity. Dr. Henry Bigelow introduced Gage to his colleagues as a great wonder of the age. Afterward, Gage sat for a plaster cast of his face (known as a life mask), which displayed the damage caused by the tamping iron.

Dr. Bigelow used Gage as part of demonstrations during his lectures. During each lecture, Dr. Bigelow carried the tamping iron onto the stage so that everyone could see that he was telling the truth about the accident. Many of the doctors attending the lectures felt that Dr. Bigelow’s claims sounded unbelievable. No doctor thought that anyone who suffered a serious head wound such as Gage’s could possibly recover. Dr. Bigelow supported his claims with multiple witness accounts, medical records, and testimony from Gage himself. Although some of the doctors doubted whether Dr. Bigelow was telling the truth, the evidence provided by the physical injuries to Gage’s head and brain were undeniable.

Fleischman discusses how people have viewed the brain’s function throughout history. For thousands of years, many were incorrect about how various organs in the body work. For instance, ancient philosophers believed that one purpose of the brain is to cool blood flowing through it. Emotions and thoughts were believed to reside primarily within the heart and other organs. By the mid-19th century, physicians understood the general layout of the brain’s major structures. However, they hadn’t developed sufficient understanding about how the brain works.

Fleischman offers a brief tour of the brain’s main components—the cortex, brainstem, cerebellum, hemispheres, and lobes. He explains that the cortex is responsible for perception, memory, language, imagination, and interpreting sensations. He says that Gage’s injury severely affected the left frontal lobe area of the cortex and destroyed approximately 25% of his total cerebral tissue. The remainder of Gage’s brain remained largely unaffected.

Scientists in Europe began to develop new insights into cellular biology, namely that all living organisms are composed entirely of cells. However, prior to 1850, the concept of neurons and synaptic transmission had not yet emerged. Therefore, physicians in 1850 didn’t understand electrical activity in the brain. They didn’t know that neurons are specialized cells capable of transmitting information via electrical impulses and chemical messengers. Fleischman describes how these cells form networks connecting billions of neurons to produce an intricate system.

Later, scientists would learn that neural connections are critical in producing conscious experience including sensation, memory, action, and emotional response. The physicians studying Gage in 1850 didn’t understand this.

Physicians in 1850 understood that injuries affecting the spine could lead to paralysis or death; therefore, Gage’s ability to survive his severe cranial injury was puzzling. Physicians debated what the damage to Gage’s frontal cortex meant.

Fleischman describes two competing views regarding how the brain functions. The first view is referred to as the “whole brain” theory. It holds that all parts of the brain function as a unified entity. If any part of this whole is damaged, another part should assume responsibility for performing its duties. Dr. Bigelow supported this view. He argued that Gage, who continued to live and function despite having lost significant portions of his cerebral matter, illuminated this.

A second group referred to itself as “localizers.” They argued that different parts of the brain control distinct types of functions. Localizers were associated with phrenology, which proposed that particular aspects of personality and cognition correspond to unique “organs” located in specific locations in the brain. These “organs” can allegedly be identified by analyzing bumps found on a person’s skull. While localizers presented their views as scientifically based, there was limited empirical data to support their proposals.

Localizers reported that Gage’s behavior was significantly altered after his accident. Dr. Nelson Sizer, a localizer, claimed that Gage used more profanity and was coarser than previously observed. Dr. Sizer also stated that Gage was difficult to get along with socially. Based on Dr. Harlow’s observations, Dr. Sizer proposed that these changes likely resulted from damage occurring in specific areas of the brain that correspond to feelings of compassion or respect toward others.

Fleischman discusses how contemporary neuroscientists have proven that both groups were correct and incorrect. There are indeed highly specific functional centers for localized processes within discrete areas of the brain. However, these areas communicate extensively with other regions of the brain. Both localizationism and holism remain accurate descriptions depending on context and perspective.