Where in Kant's ethical theory may we find principles, guidance, or at least insights, about the morality of abortion? The formula of universal law is a natural place to begin looking. There is a long tradition of focusing on Kant's formula of universal law as a principle for evaluating maxims, resting in part on the belief that Kant intends the formula of universal law to be so used (G 4:437-38).¹ It is hardly surprising that some philosophers have already turned to this principle searching for the — or at least a — Kantian view of abortion. Universalization tests promise a relatively clear and straightforward way to discern the morality of actions. The formula of universal law seems to offer a method for evaluating maxims of abortion that eschews the contentious question of whether the fetus is a person. This method also appears to render unnecessary the task of locating one duty, among Kant's vast network [End Page 547] of duties discussed in the Metaphysics of Morals, in relation to which to understand abortion.

I begin this paper with a brief look at two philosophers' attempts to use Kantian universalization to generate a general prohibition of abortion. I then explore how three interpretations of the formula of universal law's contradiction in conception test and one interpretation of the formula of universal law's contradiction in will test might evaluate abortion maxims. I show that none of these interpretations does much to generate plausible prohibitions on maxims of abortion, though one of them — Barbara Herman's interpretation of the contradiction in the will test — does allow us to think about abortion (and fetuses) in compelling ways. I close by suggesting how we may build on the insights from our examination of the most helpful universalization test, and on other resources of Kant's ethical theory, to forge a more complete picture of Kantian considerations regarding abortion.

In the end, then, this paper emerges as largely negative and preparatory: it delineates the limitations of even the most persuasive interpretations of the formula of universal law tests in shedding light on the problem of abortion, in order to point the way to potentially more fruitful approaches. These negative, preparatory tasks are crucial in view of both the prominence that Kant gives to the formula of universal law in the Groundwork for the Metaphysics of Morals, and the dominance that the formula of universal law has had within Anglo-American Kantian ethics. Achieving a clear understanding of the shortcomings of the formula of universal law for considering the morality of abortion is necessary in order to move the debate on abortion within Kantian ethics into other, more promising, areas. Moreover, the failure of this much-favored formulation of the categorical imperative to provide guidance regarding the morality of abortion is of philosophical interest in its own right.

I Two Kantian Universalization Arguments

The formula of universal law (FUL) is the first formulation of the categorical imperative that Kant introduces. It states: 'Act only according to that maxim whereby you can at the same time will that it should become a universal law' (G 4:421). FUL has a variant, the formula of universal law of nature (FULN): 'Act as if the maxim of your action were to become through your will a universal law of nature' (G 4:421). FUL is the formulation of the categorical imperative that most clearly captures the notion of morality as a categorical imperative, that is, as a universal law that commands us to act on certain principles independent of our inclination- based ends or our personal characteristics. Kant says, 'if I think of a categorical imperative, I know immediately what it contains. [End Page 548] For since, besides the law, the imperative contains only the necessity that the maxim should accord with this law, while the law contains...