It is more complex than just a one word description but that’s an argument from absurdity.
Let’s suppose we build a teleport device which can make identical copies. As in your standing in pad X then someone else is standing on pad Y that looks identical to pad X and you both respond identically.
Now, whatever that machine reads as your mind state is your actual mind state. We don’t need to make an actual copy to do exactly what you said was impossible.
To clarify, you can’t really capture an image with words but a camera can capture an image as symbols. It’s just that a person looking at those symbols can’t see the image. The same is presumably true of a mind.
Let’s suppose we build a teleport device which can make identical copies. As in your standing in pad X then someone else is standing on pad Y that looks identical to pad X and you both respond identically.
Now, whatever that machine reads as your mind state is your actual mind state. We don’t need to make an actual copy to do exactly what you said was impossible.