science

This comic is terrible and the sort of thing that gets refuted in Philosophy 1000. It's not even a good version of the same bad argument that I've heard dozens of times. The fact that it compares copying and destroying a person to falling asleep is absolutely absurd. Your brain doesn't stop functioning when you sleep, and your molecules don't instantly replace themselves each night.

The point of the Ship of Theseus thought experiment is that if you replace the parts of a ship one by one over time, never replacing more than what you keep at any one time, you can easily understand how it continues to be the same ship even if at the end of its existence it contains none of the original parts. Each part has shared experience with the others. There is continuity of the whole even if any individual part has been lost and replaced. If you replace the entire thing all at once, it is absolutely a new ship because not a single piece shared any experience with a part of the original, or a part that can be traced back to a shared existence with the original.

That continuity of experience is what matters, and in sentient creatures that extends to continuity of thought (conscious or unconscious). A person has a sense of self that doesn't end just because you lost consciousness. If you create a copy of a person and destroy the original, that sentience doesn't jump into the new body. Yes, it thinks and acts exactly as the original person did, but the original person is still dead. This only wouldn't matter to someone who lacks sentience. But then again I have always been a bit solipsistic.