If consciousness is a computation (and I think it is), and if you fork() that computation (as the article imagines as its core thought experiment), you end up with two conscious entities. I don't see the philosophical difficulty.

If consciousness is substrate independent, it can never be embodied like we are. If evolution explores solution space regardless of what science understands, it's likely minds operate on laws of physics that aren't appreciated yet. It's possible that having experience requires being real. As in the computable numbers are a subset of the real numbers, and only real life real time implementations can experience, because the having of experience can't be simulated.

Here's a relevant bit from the article:

> More generally, we acknowledge that positions on ethics vary widely and our intention here is not to argue that computational theorists who accept these implications have an irreconcilable ethical dilemma; rather we suggest they have a philosophical duty to respond to it. They may do so in a range of ways, whether accepting the ethical implications directly or adopting/modifying ethical theories which do not give rise to the issue (e.g., by not relating ethics to the experiences of discrete conscious entities or by specifying unitary consciousness as necessary but not sufficient for moral value).