> Presumably your stance here is that the fetus does not have the ability to apply defensive or retributive force, and therefore has no right to it. No, that "

> Presumably your stance here is that the fetus does not have the ability to apply defensive or retributive force, and therefore has no right to it. No, that "therefore" does not follow. One does not lose a right just because one lacks the power to exercise it. The fetus would not be wrong to employ violence to resist any attempt to kill it—though even putting it in those terms presumes a degree of conscious decision-making and self-ownership which is not in evidence. > Taken to its logical end, wouldn't this imply that any murder would not be immoral…? No. To begin with, I never said that abortion wasn't immoral or a violation of the Non-Aggression Principle. Both of those are debatable; from a libertarian point of view the answer to the latter question hinges on whether the fetus can claim self-ownership, which presumes a degree of conscious control and responsibility for the effect of one's actions on others. That is all quite abstract, however, because in practical terms it would be a violation of the NAP for anyone else to intervene. An adult, or even a young child, who found themselves harmed or threatened with harm could consent to allow someone else to fight on their behalf; or, just as importantly, could withhold that consent. (For example, they could be a pacifist and believe that fighting back would be immoral.) In the case of a murder one could look to a will or the like as evidence of the victim's wishes. For an abortion, however, there is no such evidence. Anyone responding to it with force is doing so entirely on their own, and not in self-defense, which makes them the aggressor.