Galt is the hero and main character of Atlas Shrugged, because his principles drive the action and the conflict of the story. The book explores what occurs when the thinkers go on strike. Galt conceives of the strike, initiates it, sustains it, and carries it to a successful resolution. Part of the fascination of Atlas Shrugged is that its dominant character works behind the scenes, his existence unknown to the reader, for the first two-thirds of the novel. The question invoking his name lends a legendary quality to his character, as if he were, in part, a mythological being. In a universe populated with giants, his is the character of greatest stature. The mystery shrouding the story's unfolding conflict results from the choices he makes. The strike is necessarily secretive, so the disappearance of the world's great thinkers must be a mystery to everyone outside of Galt's circle.
Galt realizes, during the implementation of communist principles at the Twentieth Century Motor Company, that the only hope of ending the mind's exploitation is by means of a strike. His insight has the potential to usher in a new historical period — to be "epoch-making."
Ayn Rand presents Galt as a man of epic proportions. She stated that the goal of her writing was the presentation of an ideal man, and that goal is reached with the figure of John Galt. He is a man of prodigious intellectual gifts — a physicist who brings about a revolution in man's understanding of energy, a philosopher who defines a rational view of existence, and a statesman who leads a strike that transfigures the social systems of the world. Two characteristics make possible the enormity of his intellectual achievements. One is his unique genius. The other is a trait that men can replicate: his unswerving rationality. Galt describes himself as "the man who loves his life," which is accurate. But above all, he is the man who perceives reality — the man who allows nothing to interfere with his cognitive apprehension of the facts. He is characterized by reference to his "ruthlessly perceptive eyes" — the eyes that honor facts and see reality for what it is, regardless of Galt's feelings about that reality.
In a signature scene, Galt tells Dagny — the woman he has loved and watched for years — what he did and felt upon learning that she was Hank Rearden's mistress. He went to observe Rearden at an industrialists' conference. Rearden had everything that Galt wanted and could have had if he hadn't chosen to strike. Rearden had his mills, his invention, his wealth, his fame, and his love relationship with Dagny. For one moment, Galt felt a tearing sense of loss. He saw what would have been his if he hadn't abandoned his motor. But Galt felt that loss for only a moment, because he then recognized the full set of facts defining the situation. He saw the burdens that Rearden carried, the impossible demands, and the forces stifling and enslaving him. He saw Rearden struggling in silent agony, striving to understand what Galt alone had understood. He saw Rearden for what he was — the symbol of the strike, the great unrewarded hero whom Galt was to liberate and validate. The scene that he describes to Dagny provides the key to understanding Galt's character. He feels intense emotion and suffers when he experiences loss, but he doesn't permit his emotions to interfere with his cognitive grasp of reality or with his actions based on that cognition. He knows that the strike is right, and no pain resulting from its consequences can defile the purity of his cognition.
What makes Galt unique is his method of using his mind — his unflinching commitment to facts, even if they are unpleasant, painful, or frightening. He functions rationally, holding an undeviating allegiance to reality that his most honest judgment grasps. Galt's life embodies a proactive eagerness to seek out truth and an inviolable willingness to accept it, no matter its content. He recognizes that man can only achieve success and happiness by revering reality. He doesn't consider facing reality a duty or something that requires tight-lipped stoicism. Instead, he celebrates reality, joyously recognizing that consistent adherence to reality is at the core of self-interest. He knows that a willful departure from reality is the essence of self-destruction.
John Galt is a hero representing the best of modern civilization — its science, its medical research, its technological progress, and its application of intellect in service to human life. He embodies the novel's essential theme: Only by means of the mind can human beings achieve prosperity on earth.
Because of the towering achievements of his intellect, it's easy to overlook the other aspects of Galt's life: his light, effortless way of moving; his passionate love for Dagny; the tenderness and concern he shows for his lifelong friends, Francisco d'Anconia and Ragnar Danneskjöld; and his respect for his teacher/spiritual father, Hugh Akston. The special bond that Galt shares with these four people shows Rand's rejection of the conventional split between reason and emotion, which holds that an individual can be either rational or emotional — he cannot be both. The poignant, understated intensity of Galt's relief on seeing Ragnar after a year of ceaseless dangers is a simple but eloquent example of a rational man's emotional life. Because Galt values the mind and its achievements, he must give his love to exalted individuals. A man of reason cannot look unmoved upon such noble souls as Francisco, Ragnar, and Dagny. A true man of the mind experiences the most intense emotional bond to such individuals because he is a man of the mind. In the character of John Galt, Ayn Rand shows that reason and emotion can and should be integrated in the human being's life.