Este é "O Extra" de Greg Egan.
A história é sobre um homem rico que faz clones de si mesmo. Os clones são alimentados e exercitados para que eles tenham corpos perfeitos, mas não tenham a capacidade de se desenvolver mentalmente.
Keeping a stock of congenitally brain-damaged clones of oneself - in the short term, as organ donors; in the long term (once the techniques were perfected), as the recipients of brain transplants - was not illegal, but nor was it widely accepted. [...] There had been legal challenges, of course, but time and again the highest courts had ruled that Extras were not human beings. Too much cortex was missing; if Extras deserved human rights, so did half the mammalian species on the planet. With a patient, skilled trainer, Extras could learn to run in circles, and to perform the simple, repetitive exercises that kept their muscles in good tone, but that was about the limit.
Quando o homem rico envelhece, ele muda seu cérebro para um dos clones. Desta forma, ele vai se dar um novo corpo fresco. No entanto, ele fica horrorizado ao descobrir que quando ele acorda após o transplante, ele está no mesmo corpo.
When, at last, one arm came under his control, he raised it, with great effort, into his field of view.
It was his arm, his old arm - not the Extra's.
He tried to emit a wail of despair, but nothing came out.
Something must have gone wrong, late in the operation, forcing them to cancel the transplant after they had cut up his brain.
Ele transplantou seu cérebro, mas não sua alma, ou suas memórias.
Of course he was dreaming. What other explanation could there be?
Unless the transplant had gone ahead, after all.
Unless the remnants of his brain in this body retained enough of his memory and personality to make him believe that he, too, was Daniel Gray. Unless the brain function studies that had localised identity had been correct, but incomplete - unless the processes that constituted human self-awareness were redundantly duplicated in the most primitive parts of the brain.
In which case, there were now two Daniel Grays.
Ele tenta dizer aos operadores que houve um erro, mas ele se vê incapaz de expressar as palavras. ele percebe que vai ficar preso como um idiota para sempre, enquanto o clone rouba sua vida dele.
He had given up trying to communicate his plight to the people around him. He knew he would never master speech, and he couldn't even manage to convey meaning in his gestures - the necessary modes of thought were simply no longer available to him, and he could no more plan and execute a simple piece of mime than he could solve the latest problems in grand unified field theory.