Come to think of it, I'm watching Author, Author right now, and why didn't
they cite Data as precedent for giving rights to artificial intelligence? Seems like the writers made an oversight.
The Doctor wasn't designed to be sentient the way Data was, but it has been well established in Star Trek mythology that non-sentient machines can become sentient by becoming more complex. I think any debate about sentience in a Star Trek series has to use the established rules of the Star Trek universe.