Thompson's "A Defense of Abortion": Key Arguments Analyzed

Introduction

The author of this piece, Judith Jarvis Thomson, supports abortion. She uses descriptive assumptions creatively and makes dramatic — even outrageous — examples as juxtapositions to develop her argument and make her points. She also employs value assumptions that are effective in her narrative. But Thomson's theses and her Socratic style of argument carry the most weight as she turns the positions of the pro-life movement upside down as a way to make her own positions shine. Thomson presents all of this two years before the U.S. Supreme Court's historic Roe v. Wade decision, which is impressive in hindsight given the intensity of the ongoing debate on abortion.

Is the Fetus a Human Being from the Time of Conception?

In her first paragraph, Thomson notes that people are expected by pro-life proponents to accept that the "fetus is a person from the moment of conception." But the premise that life begins when the egg is fertilized is "false," Thomson argues, and she uses the analogy of an acorn. Because an acorn will eventually transition into a tree, does it follow that an acorn is a tree? The logic in her position is Socratic and powerful, albeit anti-abortion advocates would likely argue that it is not a fair analogy — that human life is far more precious and deserves a moral discussion, whereas an acorn is just a tree with no human, moral, or ethical implications.

"A newly fertilized ovum, a newly implanted clump of cells, is no more a person than an acorn is an oak tree," Thomson writes (p. 1). Opponents of abortion spend much of their time arguing that the "fetus is a person," which is too "simple" a position for such a complex social issue, she insists. But, Thomson asks, what if that premise is correct — that a fetus is a person?

The fetus would then have a right to life, which is "more stringent" than the mother's right to decide what happens in and to her body. In that case, the fetus may not be killed, and an abortion cannot be morally justified. Thomson presents this line of reasoning as a way to set up her value assumption and then challenge it directly.

Does a Woman Have a Right to Abort a Fetus to Save Her Own Life?

In this section of her scholarly paper, Thomson uses value assumptions and descriptive assumptions regarding the typical arguments presented by those vehemently opposed to abortion. Consider a scenario in which a woman is pregnant but discovers she has a heart condition that, should she carry the child to term, will kill her. Thomson uses emotion to present her argument in this instance. Anti-abortion advocates argue that killing an innocent person — the fetus — would be wrong, since the fetus has not committed a crime; therefore, an abortion is not permitted. Killing an innocent child is "murder," and since murder is against the law, an abortion cannot be performed. Given this premise, it would be acceptable to let the mother die rather than kill an innocent fetus. This is an outrageous conclusion, and Thomson's emotional framing — how could anyone justify letting a grown woman die in order to save a fetus growing inside her? — comes across as very powerful.

A descriptive assumption is a belief about the way the world is. In this case, the pro-choice worldview does not accept that a woman should die in order to save her fetus. A value assumption, by contrast, is related to how the world should be. Using the anti-abortion movement's own "slippery slope" reasoning — that at all costs, a fetus must not be aborted regardless of the mother's life — against their own argument proves very effective.

Conclusion

Thomson takes on the anti-abortion arguments one by one and uses her narrative effectively to counter them. She deploys the acorn analogy with particular force: an acorn is not a tree, and therefore a newly fertilized ovum — a "newly implanted clump of cells" — does not automatically constitute a human being. She firmly engages anti-abortion premises and, rather than simply tearing them down, presents logic through analogy and juxtaposition to secure her points. There will not be — any time soon — an end to the ongoing debate about abortion. But for those who are pro-choice, Thomson's arguments ring loud, clear, and persuasive.