The killing of embryos and fetuses is intrinsically disturbing and disgusting to normal people, including me. As with other such acts — the eating of corpses, for example — an organized society needs some consensus, embodied in law, about what may and may not be done; though also (I’d argue) an understanding that that consensus is founded on nothing but those widespread common emotions — disturbance and disgust. I’d guess that most people in today’s U.S.A. would settle for unconditional abortion up to 12 weeks, conditional abortion up to 20, severely conditional thereafter. Whatever the consensus is, let’s settle on it and enforce the laws.According to this view of morality there is no position from which one can criticize any action or societal condition which commands cultural consensus. Unfortunately, this leaves us a little morally defenseless against things like slavery, or racial discrimination, or oppression in any form. I suppose someone could argue that there is no consensus in these cases, since slaves themselves, or oppressed groups, do not support their oppression. But the exclusion of parties harmed by a societal condition being excluded from the consense could hardly be a rebuttal of this point for Derbyshire, since he is excluding the unborn from his consensus when it comes to abortion.
And of course under this view you couldn't argue that there was some moral imperative to change the consensus, since, according to Derbyshire, the only moral imperative comes from the consensus itself.
Derbyshire expands on his emotive theory in another post, now positing a "module":
[W]e have, as part of our mental equipment, a module that, for any other human being, computes a sort of “potential-for-accumulating-experience” quotient, and assigns the human being a value on that basis. This module likely only kicks in when confronted with an observable human being, though. Probably our brains just didn’t evolve to have valuation modules for embryos and fetuses, which we didn’t much encounter until recently. Following on from that, I’d guess that much of the salience of the abortion issue in modern life is driven by the good-quality medical imaging that’s become available in recent decades. I’d guess, in fact, that really good quality imaging of fetuses, if cheaply and widely available, would lead to public demands for earlier limits on legal abortion terms. The theocons can metaphysic all they want, but further policy/legal changes in this zone will likely be driven by things we can see and hear, and by the effects those things have on our emotions. Metaphysics butters no parsnips.Where this "module" is in your "mental equipment" is somewhat mysterious, as is the exact evidence for the assertion in the first place, although Derbyshire seems to know an awful lot about it. The only evidence for the existence of this "module" appears to be the fact that these "emotions," which somehow, inexplicably, constitute an ought, exist.
Such is the moral philosophy you end up with when you reject metaphysics--and when you start viewing human beings as simply advanced computers complete with components and computational capabilities. One wonders why advanced computers have any rights at all, whether they can "compute" emotions or not.
What, other than the existence of a soul, makes human beings any more worthy of respect than animals--or computers?