Following on from yesterday’s post, I’d like to look more closely at the matter of potentiality.
As mentioned previously, the argument put forward by Bill Vallicella in his discussion of abortion at The Maverick Philosopher is that from the moment of conception the zygote has the potential to become a fully developed adult, a rights-possessing member of society, and that in virtue of this potential the zygote itself should be accorded the right to life. We should do this, the argument goes, because we already accord the right to life to other entities that are only potentially qualified, namely babies and small children, and therefore to deny this consideration to the conceptus is to apply the principle inconsistently.
A central assumption in this line of reasoning is that the potential for full-fledged personhood is not only present in both zygote and neonate, but is also only either present or absent, and not the sort of property that admits of degrees. In other words, Bill insists that it is wrong to say that the full-term fetus has more potential for rights-possessing adulthood than a unicellular zygote. I think this assumption is wrong.
First: it is clear to all, I will assume, that the just-fertilized ovum is not a particularly impressive organism; far less so than a fly, or a nematode worm, or any of thousands of other tiny, nonsentient creatures whose lives we think nothing of extinguishing. The zygote manifests none of the properties or characteristics that make adult humans moral — and morally considerable — entities. It has no brain; it cannot suffer. It has no mind, no will, no consciousness. It is little more than a few strands of DNA in a membranous container. Its moral significance, then, derives from the fact that it may, if the mother makes costly and laborious efforts and investment on its behalf, one day become a moral agent itself. If we care about its fate, it’s because each one of us was once such a being.
But does a zygote have the same potential for rights-possessing adulthood as a full-term fetus, or a newborn infant? I think that to insist that such potentiality is only binary in nature — just either “there” or “not there” — is a serious error. Potentiality is, I argue, the sort of thing that comes in degrees.
The example usually given is that of fragility. Fragility is the potential for an object, given the right conditions, to shatter. (Conditions matter here; obviously a just-fertilized ovum left by the side of the highway is unlikely to reach adulthood, despite whatever potentiality it may have.)
Now consider two drinking vessels. One is an eggshell-thin Tiffany wineglass, and the other is a tempered-glass cafe tumbler. Both are fragile; both will shatter if I strike them with a hammer. Both would be shipped in a carefully packed box marked “Fragile”. The wineglass, however, will shatter if it tips over in the sink, or if it is tapped with a spoon; the cafe tumbler will not.
If the glasses are both fragile — i.e., both have the potential to shatter if struck — then in what way do they differ? Not in the manifestation itself; shattering is shattering. Not in the possessing or not-possessing of the potential-to-shatter that we call “fragility”; both do indeed possess it. No, what we must answer is that while they are both fragile, the wineglass is more fragile. In other words, it possesses the potential to shatter in a greater degree than the cafe tumbler: there are vastly more possible histories in which the wineglass ends up smashed to pieces.
If this is so — that two different entities can possess the same potentiality to varying degrees — then why can’t the potential contained in a single object vary from one time to another?
Let us imagine further that one Wednesday morning the cafe tumbler is heated in a furnace and re-molded into a Tiffany wineglass. This means, then, then, that although on Tuesday it possessed the potential-to-shatter only to a moderate degree, by Thursday it has a great deal more of it. Its potential to shatter has increased over time.
If it is possible for this sort of potential to change with time, then why not for the potential personhood of the developing conceptus? Can we not say that a newborn has potential personhood in far greater degree than a day-old zygote?
How will this affect the anti-abortionist’s argument from potential?