Self-defense gives the absolute right to kill? What sort of a deranged mutant barbarian are you?
Calm down. I don't think that's what Mr. Laser Beam meant at all. And what's with the name-calling?
If he did mean what he wrote, he doesn't deserve name-calling, but a shot through the head. That sort of scum shouldn't be allowed to live.
If he didn't, I withdraw my accusation. But no apologies, for the very ambiguity there is disgusting enough.
(No, I know
Mr Laser Beam well enough to insist he does not really deserve a bullet through the head.

But I can't let statements like that stand, not even until the next reply.)
FWIW, Kirk explicitly has no right to save his life or that or his crew at any cost. He has sworn an oath to DIE to defend Federation values, and that doesn't mean he can substitute "kill" for "die" whenever he pleases.
Nor is anyone arguing that he can. But that doesn't mean he shouldn't act to save his ship and crew when he's able, provided that he does so within the confines of his position as a starship captain.[/QUOTE]
Quite so. And going for genocide is often a necessary step in protecting something as big as the UFP against threats as fantastic as those cropping up in Star Trek, but protecting a mere starship will usually have to be conducted by less drastic measures.
Out of the four cases of killing the last known example of a species, fleeing rather than fighting back was an option in three.
The death of the Salt Vampire came in the heat of the moment, though, and would have called for much more disciplined minds if the fatal outcome were to be avoided.
Fleeing the Space Amoeba was certainly an option, while going after it was necessary because of the clear, present and imminent danger of the creature wreaking further havoc - even though Kirk didn't really have realistic hopes of achieving anything, considering the
Intrepid had already failed and was deemed equal of the
Enterprise.
Hunting after the dikironium cloud was pure sport, and tactical withdrawal and regrouping would certainly have been in order: no imminent further danger came from the creature in that episode.
The Doomsday Machine would certainly have warranted further study, but a series of poor tactical choices deprived Kirk of the option of flight early on. Failing to flee towards the end of the episode was stupid, though, as there was no indication Kirk couldn't outrun the beast to the next vulnerable target and face it with backup from fifty other fighting vessels, all informed about the capabilities of the beast. "She's heading for the Rigel colonies!" didn't really create any tactical immediacy there.
Issues of self-defense vs. self-sacrifice surface more prominently in episodes like "The Apple", where Kirk would certainly have the option of yielding to Vaal, or "Return of the Archons", where he could yield to Landru. Apparently, the latter case wouldn't even be the end of his crew (although it might be a fate worse than death). Shooting one's way out of trouble sounds heroic, but when it means shooting your way through a planet-sized crowd of innocents, it's a very different matter.
Timo Saloniemi