Spock Didn't Die Here...

...although that may depend on your definitions.

Allow me to bring your attention to this passage from Spock Must Die!, the first original Star Trek novel:

"What worries me," McCoy said, "is whether I'm myself any more. I have a horrible suspicion that I'm a ghost. And that I've been one for maybe as long as twenty years."
The question caught Captain Kirk's ear as he was crossing the reck room of the Enterprise with a handful of coffee. It was not addressed to him, however; turning, he saw that the starship's surgeon was sitting at a table with Scott, who was listening with apparently deep attention. Scotty listening to personal confidences? Or Doc offering them? Ordinarily Scotty had about as much interest in people as his engines might have taken; and McCoy was reticent to the point of cynicism.
"May I join this symposium?" Kirk said. "Or is it private?"
"It's nae private, it's just nonsense, I think," the engineering officer said. "Doc here is developing a notion that the transporter is a sort of electric chair. Thus far, I canna follow him, but I'm trying, I'll do mysel' that credit."
"Oh," Kirk said, for want of anything else to say. He sat down. [The author goes on a bit about McCoy's divorce, McCoy's and Kirk's roles, etc. for two paragraphs.]
"Somebody had better fill me in. Doc, you've said nine times to the dozen that you don't like the transporter system. In fact, I think 'loathe,' is the word you use. 'I do not care to have my molecules scrambled and beamed around as if I were a radio message.' Is this just more of the same?"
"It is and it isn't," McCoy said. "It goes like this. If I understand Scotty aright, the transporter turns our bodies into energy and then reconstitutes them as matter at the destination..."
"That's a turrible oversimplification," Scott objected. ... "What the transporter does is analyze the energy state of each particle in the body and then produce a Dirac jump to an equivalent state somewhere else. No conversion is involved-if it were, we'd blow up the ship.
"I don't care about that," McCoy said. "What I care about is i my state of consciousness-my ego, if you like. And it isn't matter, energy, or anything else I can name, despite the fact that it's the central phenomenon of all human thought. After all, we all know we live in a solipsistic universe."
[In the interest of brevity and maintaining the spirit of fair use, I'll just direct you to Wikipedia's solipsism article, and generally suggest that he's being philosophical and that he's talking about individuality and uniqueness.]
[Kirk said,] "...But you still haven't answered my question. What's all this got to do with the transporter?"
"Nary a thing," Scott said.
"On the contrary. Whatever the mechanism, the effect of the transporter is to dissolve my body and reassemble it somewhere else. Now you'll agree from experience that this process takes finite, physical time-short, but measurable. Also from experience, that during that time period neither body nor consciousness exists. Okay so far?"
"Well, in a cloudy sort of way," Kirk said.
"Good. Now, at the other end, a body is assembled which is apparently identical with the original,is alive, has consciousness, and has all the memories of the original. But it is NOT the original. That has been destroyed."
"I canna see that it matters a whit," Scott said. "Any more than your solipsist position does. As Mr. Spock is fond of saying, 'A difference which makes no difference is no difference.'"
"No, not to you," McCoy said, "because the new McCoy will look and behave in all respects like the old one. But to me? I can't take so operational a view of the matter. I am, by definition, not the same man who went into a transporter for the first time twenty years ago. I am a construct made by a machine after the image of a dead man-and the hell of it is, not even I can know how exact the imitation is, because-well, because obviously if anything is missing I wouldn't remember it."

Serious moral discussions are what one expects from author James Blish, and all things considered, the issue with the transporter is a doozy. (In fact, Michael Wong seems to take at least some issue with it; at the very least he believes that the inhabitants of the Star Wars galaxy would. In his crossover fanfic Conquest, he presents the Imperials and Rebels alike as viewing transporter travel as an abomination, though they seem to find the idea of using them for industrial and shipping purposes acceptable.)

Also, if you've never read this book and are wondering what in the world this has to do with Spock dying, pretty much it's (SPOILERS AHEAD) because a transporter accident/experiment makes a Spock clone. An evil Spock clone. And Spock totally kills that guy.

-Signing off.