"Fine."
He walked back over to the window, but this time he looked at the horizon, not at the street.
Farnsworth had called him "Bart". It's funny, Stanton thought, how habit can get the best of a man. Farnsworth had known the truth all along, and now he knew that his patient—former patient—was aware of the truth. And still, he had called him "Bart".
And I still think of myself as Bart, he thought. I probably always will.
And why not? Martin Stanton no longer existed—in fact he had never had much of a real existence. He was only a bad dream; only "Bart" was real.
Take two people, genetically identical. Damage one of them so badly that he is helpless and useless—and always only a step away from death. It is inevitable that the weaker will identify himself with the stronger.
The vague telepathic bond that always links identical twins (they "think alike", they say) becomes unbalanced under such conditions. Normally, there is a give-and-take, and each preserves the sense of his own identity, since the two different sets of sense receptors give different viewpoints. But if one of the twins is damaged badly enough something must happen to the telepathic link. Usually, it is broken.
But the link between Mart and Bart Stanton had not been broken. It had become a one-way channel. Martin, in order to escape the prison of his own body, had become a receptor for Bart's thoughts. He felt as Bart felt—the thrill of running after a baseball, the pride of doing something clever with his hands.
In effect, Martin ceased to think. The thoughts in his mind were Bart's. The feeling of identity was almost complete.