Aquinas and Homosexual Sex – Part 4: The Logic of Applied Ethics

Bradley Bowen | December 25, 2020

This will be a fairly short post about the logic of the core argument in Tim Hsiao’s article “A Defense of the Perverted Faculty Argument against Homosexual Sex” (hereafter: PFA). I take it that the core argument of that article can be summarized in this categorical syllogism:

4. All sexual activity that is not open to the creation of new life is immoral.

A. All homosexual activity is sexual activity that is not open to the creation of new life.

THEREFORE:

7A. All homosexual activity is immoral.

AN ANALOGOUS ARGUMENT IN APPLIED ETHICS

Let’s set that argument aside for now, and consider an analogous categorical syllogism, also in the area of applied ethics:

10. All cases of pregnancy in which maintaining the pregnancy until birth would produce significantly greater UTILITY than terminating the pregnancy by having an abortion are cases of pregnancy where it would be immoral to terminate the pregnancy by having an abortion.

11. All cases of pregnancy where the pregnancy does not put the pregnant woman’s life in serious danger are cases of pregnancy in which maintaining the pregnancy until birth would produce significantly greater UTILITY than terminating the pregnancy by having an abortion.

THEREFORE:

12. All cases of pregnancy where the pregnancy does not put the pregnant woman’s life in serious danger are cases of pregnancy in which it would be immoral to terminate the pregnancy by having an abortion.

I do not agree with this argument. This argument for the immorality of abortion seems like a very dubious argument, even for someone who accepts utilitarianism as being the true or correct theory of morality. Maximizing utility would seem to be an argument that supports the morality of having an abortion, rather than being an argument against abortion. Furthermore, even if maintaining SOME pregnancies until birth that do not put the pregnant woman’s life in serious danger would produce significantly greater utility than having an abortion, this is certainly not going to be so in ALL cases of pregnancy that do not put the pregnant woman’s life in serious danger. Nevertheless, this argument illustrates the form of many important arguments in the area of applied ethics:One of the premises asserts a normative claim that rests upon an ethical theory, in this case utilitarianism:

10. All cases of pregnancy in which maintaining the pregnancy until birth would produce significantly greater UTILITY than terminating the pregnancy by having an abortion are cases of pregnancy where it would be immoral to terminate the pregnancy by having an abortion.

The other premise asserts a factual claim about particular actions or kinds of action:

11. All cases of pregnancy where the pregnancy does not put the mother’s life in serious danger are cases of pregnancy in which maintaining the pregnancy until birth would produce significantly greater UTILITY than terminating the pregnancy by having an abortion.

The conclusion of this argument in applied ethics, makes a moral judgment about a specific kind or category of action:

In order to understand this argument in applied ethics about abortion, one must understand the key terms or categories that make up the statements in the argument:

cases of pregnancy that do not put the pregnant woman’s life in serious danger
maintaining a pregnancy until birth
terminating a pregnancy by having an abortion
action X will produce significantly greater UTILITY than action Y
immoral [actions]

The point of an argument is to provide a good reason to believe the CONCLUSION of the argument. So, one cannot understand an argument unless one understands the meaning of the CONCLUSION of the argument. We cannot understand this argument about abortion unless we understand the meaning of the CONCLUSION of this argument about abortion, and we cannot understand the meaning of the CONCLUSION of this argument unless we understand the key terms or categories that make up the CONCLUSION:

cases of pregnancy that do not put the pregnant woman’s life in serious danger
immoral [actions]
terminating a pregnancy by having an abortion

Because this argument about abortion is based on a utilitarian theory of ethics, it is tempting to define the term “immoral” in terms of utilitarianism. For example, one might be tempted to understand the meaning of the term “immoral” in the CONCLUSION of this argument as follows:

Action A is immoral IF AND ONLY IF: some alternative action to action A would produce significantly greater UTILITY than action A.

However, it seems to me that defining the term “immoral” in terms of utilitarianism would be a mistake, because this would make the key normative premise of the argument TRUE BY DEFINITION. Not only would the normative premise be TRUE BY DEFINITION, but it would be obviously TRUE BY DEFINITION. We can see that this is so by substituting the above definition for the term “immoral” in the normative premise and in the conclusion of the above argument:

10A. All cases of pregnancy in which maintaining the pregnancy until birth would produce significantly greater UTILITY than terminating the pregnancy by having an abortion are cases of pregnancy where there would be an alternative action to terminating the pregnancy by having an abortion which would produce significantly greater UTILITY.

THEREFORE:

12A. All cases of pregnancy where the pregnancy does not put the pregnant woman’s life in serious danger are cases of pregnancy where there would be an alternative action to terminating the pregnancy by having an abortion which would produce significantly greater UTILITY.

There are at least two problems here.

First, premise (10A) is obviously TRUE BY DEFINITION, whereas the original premise (10) was not TRUE BY DEFINITION, at least not obviously so. The original premise (10) was NOT obviously true, and required evidence or reasons to show that it is true.

Second, one could accept the conclusion (12A) and still reject the original conclusion (12), because one could accept the idea that maintaining the pregnancy in such cases would “produce significantly greater UTILITY” than having an abortion, and yet reject the view that having an abortion is immoral in such cases. One could accept (12A) and yet reject (12) because one might reject the utilitarian theory of ethics (for example).

Therefore, it would be a mistake to define the word “immoral” in the conclusion of the argument against abortion in terms of the utilitarian theory of ethics.

Because this argument in applied ethics is analogous to Hsiao’s core argument against “homosexual activity”, it would also be a mistake to define the term “immoral” in the conclusion of his core argument in terms of the Natural Law theory of ethics. Doing so would render one of his key premises obviously TRUE BY DEFINITION, and it would make it so that one could accept the “clarified” interpretation of his conclusion while consistently rejecting the view that “homosexual activity” was immoral.