I have yet to witness anyone successfully justifying taking a life of another intelligent living being with or without the big words on this board. If you want to kill - explain what gives you the right to do it.
The "I'm a Phd in Philosophy" approach without demonstrating some impressive intellectual capacity, a clear vision or ability to defend one's stand on each possible level doesn't prove anything other than a blatant waste of time and money spent on over-educating or better mis-educating of an individual.
Resorting to established doctrines to defend one's views often happens when one's position is otherwise undefendable. Even then, those doctrines tend to collapse, showing them for what they really are - only a thought theory made by another member of the human race, thus being susceptible to errors. Every philosophical doctrine has it's weak points. If any one of them wouldn't - then we'd at last have a final solution, an undisputable authority on everything. And we don't.
The right to kill is an action and thus a person performing such an act or supporting it should be able to successfully justify it. So, the right to kill anyone or anything should be successfully defendable either through a philosophical doctrine or through the simplest words yet it is repeatedly not happening.
For your "philosophical doctrine" approach there is a "reductio ad absurdum" counterapproach, the one weapon that has you unmasked and forced to defend your principles on basic levels... and as the name says it leaves your arguments reduced to absurdity. Killing whales is right! Yes. Sure... Nonsense.
I'll admit: it was fun writing this post.
I'm looking forward to reactions to this, but if you decide to use the "evasive broken record" tactics, do not expect an answer from me. Not worth my time.
This thread is off topic as it is, anyway.