A Ghost Is Not Just a Soul With a New Name
Ghost in the Shell uses "ghost" as the word for the conscious self inside a cybernetic body, but the film deliberately refuses to turn that into a clean scientific definition. Motoko can point to memories, personality, instinct and the feeling that she is herself, yet none of those gives her proof that the self she experiences is original or even uniquely human.
That uncertainty is the point. The film lives in a world where bodies can be manufactured, brains can connect directly to networks and memories can be edited. Once those things become normal, saying "my ghost proves I am me" only moves the question one step deeper.
Why it matters
The film is not asking whether Motoko has enough humanity left. It is asking what evidence anyone has that their own identity is as stable as they think it is.
The Shell Is Replaceable, but That Does Not Make It Meaningless
SPOILER!
Myth: replaceable cybernetic bodies mean the film treats the body as irrelevant.
Motoko's body is an artificial shell built to be repaired, replaced and upgraded. The opening credits show that body being assembled piece by piece, making her physical form look less like something she was born into and more like something manufactured around her.
It would be easy to read that as the film saying the body no longer matters. The opposite is closer to what we actually watch. Motoko feels confinement through the body, tests its limits by diving, tears it apart trying to overpower the tank and finally wakes in a completely different shell.
Why it matters
The body is replaceable, but every change in body alters how Motoko experiences herself. Replaceable does not mean irrelevant.