We don't have to revere every block of rough marble because another Michaelangelo could come along and sculpt it into something as wonderful as his David; we don't have to treasure every scrap of canvas because the next Picasso is going to use it for a masterpiece. The value isn't in the raw materials, but in the pattern, the skill, the art put into it. Similarly, those cells [i.e., human zygotes, embryos and fetuses] are simply the raw clay that the process and time will sculpt into something that is worth love and care [i.e., a valuable human being].
Which is more important, the pigments or the painting? Even worse, do you think the pigments are the painting?
The analogy is misleading because a human being is not constructed from the outside, like a sculpture, but rather develops itself from within. An embryo is not raw material that may be used to form a human being, but rather a whole, self-directing organism (a human being) programmed to develop itself through the different stages of human life. A five-year-old is not a half-formed human being, like a half-finished painting, but rather a full-fledged member of our species who remains the kind of thing she is even as she grows and changes. Put simply, a living organism is a vastly different kind of thing than a constructed object.
Moreover, unlike sculptures, we don't value human beings for their artistic beauty. We value them independently of their looks, abilities, skills, etc. When we do otherwise, we end up excluding certain classes of human beings from full moral respect and protection based on morally trivial characteristics such as race, sex and handicap. This is a flat-out rejection of human dignity and equality, and the basis for such atrocities as slavery and the Holocaust.
Note that Prof. Myers' criterion for moral worth is awfully subjective; one must be "sculpt[ed] into something that is worth love and care." He adds this: "Notice how clever I was in not saying precisely when the fetus becomes a human being? That's because there is no sharp magical border, it's grey and fuzzy all the way. That's a social and personal decision."
So, apparently, whether something or someone counts as a valuable human being is "a social and personal decision." But what about the mother who personally decides her newborn baby is not yet a human being -- may she kill him? Or the culture that sees people in wheelchairs as "broken sculptures" no longer "worthy [of] love and care"?
Unlike many pro-choice bioethicists and philosophers (perhaps because he's not a trained bioethicist or philosopher), Myers doesn't offer some objective criteria (however arbitrary and inadequate, on the pro-life view) for distinguishing between humans who are rights-bearing persons and those who aren't. He just says it's "a social and personal decision," and this amounts to a radical ethical relativism.
And on that view, his last paragraph actually makes sense:
Some people are 'uneasy' about the whole abortion thing. Fine; don't get one. Your personal feelings of yuckiness shouldn't be a factor in deciding what other people do. Churches make me queasy, but I'm not planning to criminalize attendance.
But our claim is not that we don't like abortion; it's that abortion is morally wrong, whether we like it or not. Myers has reduced our objective moral claim to a claim of mere personal preference, as in the slave owner who tells the abolitionist: "Don't like slavery? Fine; don't own a slave."
