Consider first the way "Pro-Life" campaigners advocate on behalf of the person that would come to be in the future if an aborted foetus were allowed to come to term (hence the perspective of abortion as murdering a baby). This is a particular metaphysical position, one that their opponents do not share. "Pro-Life" supporters sometimes attempt to support their case by making a parallel between slavery and abortion, noting the similar arguments used in both cases. The tacit assumption here seems to be: since we discarded slavery as unjust, so we must come to discard abortion as unjust. (It is worth noting that animal activists deploy identical arguments).
Now compare an example from a different part of the culture wars. Humanist groups have recently decreased their use of the claim that "religion is brain-washing" and instead assert that raising a child in a religious tradition is tantamount to child abuse. Children, they say, should have the right to make their own religious choices when they grow up. Dawkins argues that just as feminists were involved in "consciousness-raising" on the issue of their rights, so Humanists are engaged in "consciousness-raising" in suggesting parents should not teach their religious traditions to their children. This argument is treated as self evident by its proponents, just as the case against abortion is treated as self evident by its opponents.
In both cases the same kind of manipulative argumentation is taking place: a previous historical change in our ethics is compared to a person's current beliefs and concluded to be parallel, with the inevitable conclusion that in the future everyone will share these beliefs. The "Pro-life" case makes an appeal to future people who are at least plausible – we are not asked to imagine anything more than that they will be born; the Humanist case goes further by making an appeal concerning possible people. Children raised without religion will exist in an ethically superior world, it is claimed, but this argument rests on the belief that it is immoral for parents to pass on their ethical and metaphysical beliefs to their children when they have a traditional source. Without a prior prejudice against religion this assertion is nonsense, and either way it is wildly at odds with the notion of freedom expressed by our Human Rights accords.
Part 21 of 23 in the Pentenary series.