Don Marquis: "Why Abortion is Immoral"

Don Marquis develops a theory of personhood that includes the idea of the value of a future like ours, a form of potentiality argument.

source: http://www.philosophy.umd.edu/Faculty/SKerstein/140s09/marquis.html

I. Marquis' Main Goal

"The purpose of this essay is to develop a general argument for the claim that the overwhelming majority of deliberate abortions are seriously immoral" (183)

II. A Standoff between Anti-abortionists and Pro-choicers

"The anti-abortionist charges, not unreasonably, that pro-choice principles concerning killing are too narrow to be acceptable; the pro-choicer charges, not unreasonably, that anti-abortionist principles concerning killing are too broad to be acceptable." (185)
"If it is legitimate for the pro-choicer to demand that the anti-abortionist provide an explanation of the connection between the biological character of being a human being and the wrongness of being killed . . . then it is legitimate for the anti-abortionist to demand that the pro-choicer provide an explanation of the connection between psychological criteria for being a person and the wrongness of being killed . . ." (187)

III. Marquis' Anti-Abortion Argument

Preliminaries:
Assumption: It is typically seriously wrong to kill us (adult human beings). (189)
What makes it wrong? Here's one central thing: killing us deprives us of the value of our future. It deprives us not only of what we value now and would have, given our current predilections, valued later, but also of what we would have come to value. (190)
A few implications of Marquis' account of a central wrong-making feature of killing: (Marquis takes these implications to bolster account. (190))
It is seriously wrong to kill children and infants. (191)
It is not the case that only biologically human life can have great moral worth. (191)
It might be seriously wrong to kill some currently existing non-human mammals. (191)
The Future-Like-Ours argument (192-193): Depriving a being of the value of a future like ours makes killing it wrong. Killing a fetus deprives it of the value of a future like ours. So killing a fetus is wrong.

IV. Clarifications

The crucial moral category in Marquis' argument is not that of a person or a potential person. It is rather the category of "having a valuable future like ours" (192).
In order to establish the conclusion that the vast majority of abortions are wrong, Marquis does not need to show that a necessary condition of the wrongness of killing some being is that it deprive it of the value of a future like ours. He needs merely to show that asufficient condition of the wrongness of killing some being is that it deprive it of this value. (194-195)

V. Objections Marquis Considers to his Argument

A necessary condition for the wrongness of killing a being is that doing so interfere with the fulfillment of the being's desire to go on living. But fetuses don't have a desire to go on living. So killing them is not wrong. (195-196)

Marquis' response?

Only victims can be wronged. A victim must have sentience. But embryos don't have sentience. An embryo is thus not a victim and can't be wronged. So it does not wrong an embryo to have an abortion. (199)

Marquis' response?

Contrary to what Marquis contends, it's not the case that depriving a being of the value of a future like ours is wrong. For if Marquis' contention were true, then contraception would be wrong. And that's absurd. (201