Here is an argument I presented over a Facebook post on abortion.
- If you are a human being, then you are part of the moral community.
- A fetus is a human being.
- Therefore, a fetus is part of the moral community.
Justification of premises:
Either a human being is part of the moral community in virtue of the kind of thing it is or by a notion of personhood. The assumption is that humans are intrinsically valuable in virtue of the kind of thing they are. They are not valuable because they exhibit certain accidental properties. However, the capacity to have these properties are essential to the substance human being; the manifestation of them are accidental in the sense that if a human being were to lose it’s ability to be conscious, self-aware, or rational, it would not cease to be human since the capacities would exist in a state of potency in the nature of the substance.
Why wouldn’t they be valuable/moral based on the actualization of accidental properties? I think this leads to problematically absurd results. Suppose we allow the notion of “personhood” to be the deciding factor of moral worth and value. One of the assumptions of this is to say that there is a disconnect in the type of being a human is i.e., a composite of matter/form (body/soul). The soul is this independent substance or thing that is the personhood of a being. Moreover, it would also follow from this that there can be human non-persons. What does personhood mean? For some, it’s the exhibition of certain accidental properties such as rationality, self-awareness, ability to have memory, etc. So, X is a person if and only if X exhibits certain accidental properties. But these accidental properties manifests itself in various degrees. That is, one person could manifest self-awareness more than another, or one person can manifest rationality more than the other. So, it seems that it follows that if X exhibits certain accidental properties, then these properties will vary to a degree. It thus follows that personhood varies to a degree. One person would be more morally valuable than another. But this is obviously false. We are equal in moral value. Thus, we must reject our assumption of this notion of personhood. And thus we are justified in the assumption that a human is intrinsically valuable in virtue of the kind of thing it is.
Now, because we are beings capable of using our intellects and choosing by nature of what we are, we are able to choose to fulfill our good or not. To not do so is to act wrong. Thus, morality applies to human beings and thus they belong to the moral community.
I am going to take this premise for granted and assume that you really do take science prima facie and that a fetus is a member of the species homo sapiens.
This it follows form premise one and two that a fetus is part of the moral community.
A moral community is simply all moral agents.
Now, being part of the moral community entitles you to rights. We take the right to live as being the most basic of human goods because without life, there’s no way we can seek other goods (we’d be dead) such as health, knowledge, and liberty. Any right is there to allow human beings to flourish by protecting their attainment of goods like health and knowledge, to name a few. It follows then that since the fetus is part of the moral community and anything part of the moral community has rights, that the fetus has a right, and one of these is the right to life.