Many of us believe the government should not prohibit women from having abortions, at least not in the first trimester. We think the freedom to have an abortion is important because an unwanted pregnancy imposes significant physical and psychological burdens, and may negatively affect a woman’s life in important ways. These burdens could be avoided by abstaining from sexual intercourse altogether, but sexual abstinence of this kind, many of us think, is also a significant burden. We value the freedom to have an abortion highly, then, because its occasional exercise is necessary for a person to avoid an unwanted pregnancy while remaining sexually active. Perhaps we always view the exercise of this liberty with some regret, believing that all human life., even in its very early stages, has some value. But we think the value of the freedom to laave an abortion nonetheless outweighs the value of the life ended by its exercise. So we believe the government should not limit this liberty but should recognize and protect it.

Thomson argues that it is wrong to oppose the right to abortion even if one believes that abortion is wrong. But is it?

This is not, however, what everyone thinks. Some believe the government should prohibit women from having abortions even in the first trimester. They may agree that both unwanted pregnancy and sexual abstinence impose burdens, but they believe nonetheless that the value of human life, even in very early stages, is so great as to outweigh the value of the freedom to have an abortion. They therefore believe that the government should prohibit abortions in order to protect embryonic human life rather than protect the freedom of women to have abortions.

Current constitutional law favors the first, “pro-choice” position, and this legal situation may never change. Those of us who endorse this position may still wonder, though, whether it is grounded solely on the particular system of values which we happen to endorse, which those who disagree with us may reasonably reject, or whether it is also grounded on a moral principle which every reasonable person must accept. If we hope that those who think abortion is morally wrong will eventually accept a constitutional right to an abortion nonetheless, is our hope simply that they be reasonable or is it rather that they betray their reasonable moral convictions and thereby compromise their moral integrity?

Judith Jarvis Thomson argues that it is wrong to oppose the right to abortion even if one believes that abortion is wrong. She argues from the principle—which I will call “Thomson’s principle”—that it is wrong for a democratic government to limit a fundamental liberty for reasons that those whose liberty is limited can reasonably reject. She then maintains that the freedom to have an abortion is fundamental—because necessary for women’s equality — and that it is reasonable for women to reject the reasons for limiting this liberty—because, while it is not unreasonable to believe that fetuses have a right to life, it is also not unreasonable to believe they do not. This argument would show that it is unreasonable to oppose the right to have an abortion, then, if Thomson’s principle were itself one that, no one could reasonably reject. But is it?

Consider conscription by the United States Government in the Civil War and the First and Second World Wars. It seems that those conscripted could reasonably have rejected the reasons for conscription. These were not, after all, defensive wars, strictly speaking—not for the United States. Furthermore, the freedom to refuse military service is fundamental in the morally relevant sense. That is, there are reasons of great, though perhaps not overriding, moral weight for the government to recognize and protect this freedom. Thus, if the freedom to have an abortion is fundamental, this is due largely to the objective physical and psychological burdens of unwanted pregnancy, and the objective physical and psychological burdens of compulsory military service are at least as great. Thomson’s principle thus seems to imply that it was wrong for the US Government to impose the draft in these wars. And some would no doubt agree. Many, though, would not. And if it is reasonable to believe the draft was justified, then it is reasonable to reject Thomson’s principle.

What is wrong with laws that prohibit abortion in the first trimester, it may now be said, is not that they limit a fundamental liberty for a reason that those whose liberty is limited may reasonably reject as insufficient, but that—unlike conscription in these wars—they limit a fundamental liberty for a reason that those whose liberty is limited may reasonably reject as having no moral weight at all. But is this true?

Thomson is surely correct to claim that a person can reasonably reject the claim that human embryos have a right to life. So a person may reasonably believe that only beings with actual interests have rights and that embryos have no actual interests. It does not follow, though, that a person may reasonably reject every reason for limiting abortions as having no moral weight. So a whaler might reasonably reject as having no moral weight the reason for limiting his freedom to whale that whales have a right to life. But he must still accept as having some moral weight the fact that whaling kills animals for whom some people feel a special affinity and may result in the extinction of species some people value highly. Likewise any reasonable person must, it seems, accept as having some moral weight the fact that abortion ends a human life with the potential for a full human life—a life that many regard as sacred. (Indeed, Thomson herself seems to suggest as much when she insists, albeit unconvincingly, that no woman has an abortion thoughtlessly.) So while laws that prohibit abortion limit a fundamental liberty for reasons that those whose liberty is limited may reasonably reject as insufficient, they do not do so for reasons that anyone could reasonably reject as having no moral weight at all.

Thomson’s thought, though, may be that it is wrong for a democratic government to limit a fundamental liberty for any reason other than to protect someone’s rights, and then only if no one can reasonably reject the claim that someone’s rights would better be protected by interfering with this liberty. This would seem to address the conscription objection, since conscription in our great wars was arguably necessary to protect people’s rights. And yet it would still imply that it is wrong for a democratic government to limit the freedom to have an abortion, since it is reasonable to reject the claim that human embryos have rights. But is Thomson’s principle now, in this form, one that no one could reasonably reject?

Consider the freedom of the Amish not to send their children to public high school. Given the importance to the Amish community of regulating its own affairs and perpetuating itself, and the historic commitment of our govenment to religious liberty, it seems that there are reasons of great moral weight for the government to recognize and protect this liberty. Furthermore, it seems that Amish parents could reasonably reject the claim that interference with this liberty is necessary to protect their children’s rights. Their children’s rights in education are fully protected, they might reasonably hold, as long as their education effectively prepares them to get along with others on a basis of mutual respect and to make their own way in the world should they want to do so, which the Amish education succeeds in doing (better, it seems, than much public education). Thomson’s principle thus apparently implies that it is wrong for a democratic government to interfere with the freedom of the Amish not to send their children to public high school. And this corresponds to the position of the Supreme Court in Wisconsin v. Yoder. Many liberal thinkers reject this position though. And if they are not unreasonable to reject it, then it is not unreasonable to reject Thomson’s principle.

There are two ways for someone who supports a right to abortion to view those who oppose it. One is to think that they are unreasonable because there is only one reasonable way of balancing the relevant values and this supports a woman’s right to choose. The other is to think that there is more than one reasonable way of balancing the relevant values, and that one reasonable balance supports the legal protection of early human life. Perhaps the first, less forgiving, view is the correct one. Thomson’s recent essay pursues one strategy that might show it is. There are reasons to doubt this strategy succeeds, however. And this suggests that those of us who support a woman’s right to choose must still hesitate before we judge that those who disagree with us are unreasonable.

I thank Jeffrie Murphy and Joan McGregor for comments.