A scientist has a machine that simulates his brain and it is calibrated perfectly. He has a switch around his waist that can switch from controlling his body by his brains to by this machine. And though it shouldn't matter who is controlling the body, because they do exactly the same things and have the same thoughts, they both (brain and machine) yearn for the fact of knowing they are in control and not the other. And all that they have to know who is in control, is the knowledge of the position of the switch.

In an interview with a science journalist, where the scientist keeps insisting that it doesn't matter who is in control, as they both always have the same thoughts, the interviewer keeps taunting the him to turn the switch and let the other take control.

The subject keeps being very reluctant to turn the switch, but eventually does so, because the interviewer persuaded him. And then the scientist directly becomes overwhelmed with joy and gloats about finally being in charge of the body again.

  • Hi, welcome to SF&F. When and where did you see this? Since you describe it as a "show" I tagged it tv but if it's a web series or something else we can retag it.
    – DavidW
    Commented Dec 7, 2023 at 23:34
  • I'm pretty sure it was on tv. But it could have been like 20 years back or so. Not sure if it was a series, movie or a short. Maybe even Outer Limits or Twilight Zone
    – nl-x
    Commented Dec 7, 2023 at 23:49
  • I don't recognize it as an OL episode, but I could have forgotten some.
    – DavidW
    Commented Dec 8, 2023 at 0:08
  • 1
    This sounds extremely similar to Greg Egan's short story Learning to be me, collected in Axiomatic.
    – Stef
    Commented Dec 8, 2023 at 16:54

1 Answer 1


This appears to be a duplicate of this question Short story where the protagonist’s brain has a switch between two selves

The answer is Daniel Dennett's "Where Am I?" which is available here.

Relevant quote

In any case, every time I’ve flipped the switch so far, nothing has happened. So let’s give it a try … “THANK GOD! I THOUGHT YOU’D NEVER FLIP THAT SWITCH! You can’t imagine how horrible it’s been these last two weeks—but now you know; it’s your turn in purgatory. How I’ve longed for this moment! You see, about two weeks ago—excuse me, ladies and gentlemen, but I’ve got to explain this to my … um, brother, I guess you could say, but he’s just told you the facts, so you’ll understand—about two weeks ago our two brains drifted just a bit out of synch. I don’t know whether my brain is now Hubert or Yorick, any more than you do, but in any case, the two brains drifted apart, and of course once the process started, it snowballed, for I was in a slightly different receptive state for the input we both received, a difference that was soon magnified. In no time at all the illusion that I was in control of my body—our body—was completely dissipated. There was nothing I could do—no way to call you.

Note that the other version is compassionate, not gloating - but otherwise the scenario is identical

  • 2
    You are right. It is it. But I've seen this so long ago, that the part where "THANK GOD! I THOUGHT YOU’D NEVER FLIP THAT SWITCH!" was what I remembered most, and I took it as gloating. But now that I see it again, that is a false memory.
    – nl-x
    Commented Dec 8, 2023 at 10:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.