Body is not mind. Mind may or may not be a product of biology but it’s still not a body.
If l cut myself, l don’t control if my body will heal it or not. But l do have a control not to cut myself in a the first place.
Method to determine proper justification would be: Beings level of sentience minus how much the killing of that being benefited the survival/well being of another.
Also, if person couldn’t act rationally, they cannot be morally guilty.
l think that every person could agree with that.
It’s not immoral to kill in animal for food if person is starving, but its immoral to just kill an animal for no reason or pleasure.
If there were two starving people, one eating another to survival wouldn’t be considered immoral.
`