The argument on whether abortion is morally permissible has been considered for years. Most philosophers incline to accept moral principle that it is always prima facie seriously wrong to end the life of a person in normal circumstances. The personhood of an embryo and foetus has somehow invoked another controversial issue on whether they are kind of beings, or persons, that it is seriously wrong, for any sake, to end their life. Both the anti-abortionist side and pro-choicers side can only give equally vague boundary on claiming that foetus is a person, or not so. However, as we will find out later in this essay, the problem of whether a foetus is a person, or whether a foetus has serious right to life, does not significantly affect the consideration of abortion under Thomson’s account.

The argument of the personhood of foetus will just stay at a standoff if there is no clear definition or lists for what characteristics make a thing a person. When we draw line to represent the development of a human being from the state of conception to the point that a baby is born, it will be arbitrary to choose a point which the thing inside a mother is a person after that point and not a person before that point. Moreover, the opposite of abortion may suggest that a foetus, even at the moment of conception, is a person because of their potential future, meanwhile, the supporters of abortion may insist that a foetus has not yet become a person because it lacks of some characteristics that a person need. Again, there will be an endless argument since no certain guide for personhood is established. Many anti-abortionists spend too much time on explaining that a foetus is a person and thus has right to life just like us. This seems a right track on arguing against abortion but hardly to prove precisely that abortion is morally impermissible. However, the personhood of a foetus