For the purposes of this debate, you have obtained a small, portable
device with two buttons: A “save” button and a “return” button. When you hit
the “save” button, you are able to save the current time point, like in a video
game. When you hit the “return” button, your life will return to the last time
point you saved. The machine will not erase any of your memories. If you do not
keep and use the device, it will eventually blow up on its own