The philosophical aspects of the abortion debate are logical arguments that can be made either in support of or in opposition to abortion. The philosophical arguments in the abortion debate are deontological or rights-based. The view that all or almost all abortion should be illegal generally rests on the claims that (1) the existence and moral right to life of human beings (human organisms) begins at or near conception-fertilization; that (2) induced abortion is the deliberate and unjust killing of the embryo in violation of its right to life; and that (3) the law should prohibit unjust violations of the right to life. The view that abortion should in most or all circumstances be legal generally rests on the claims that (1) women have a right to control what happens in and to their own bodies; that (2) abortion is a just exercise of this right; and that (3) the law should not criminalize just exercises of the right to control one's own body and its life-support functions.
Although both sides are likely to see the rights-based considerations as paramount, some popular arguments appeal to consequentialist or utilitarian considerations. For example, anti-abortion groups sometimes cite alleged medical and psychological risks of abortion, such as the existence of post-abortion syndrome or the abortion–breast cancer hypothesis. On the other side, abortion-rights groups say that criminalizing abortion will lead to the deaths of many women through "back-alley abortions", that unwanted children have a negative social impact, or conversely cite the legalized abortion and crime effect, and that reproductive rights are necessary to achieve the full and equal participation of women in society and the workforce. Consequentialist arguments on both sides tend to be vigorously disputed, although they are not widely discussed in the philosophical literature.
Contemporary philosophical literature contains two kinds of arguments concerning the morality of abortion. One family of arguments relates to the moral status of the embryo—whether or not the embryo has a right to life, in other words whether the embryo is a person in a moral sense. An affirmative answer would support the (1) claim in the central anti-abortion argument, while a negative answer would support the (1) claim in the central abortion-rights argument. Another family of arguments relates to bodily rights—the question of whether the woman's bodily rights justify abortion even if the embryo has a right to life. A negative answer would support claim the (2) claim in the central anti-abortion argument, while an affirmative answer would support the (2) claim in the central abortion-rights argument.