Why? Maybe I'm juat clueless about this type of thinking because abortion, like guns, is not that much of an issue in my country and seems more like an American obsession, but is it really hard to accept that new facts have been learned since priests thousands of years ago wrote a book?
Apparently it's no harder than it is to accept that just because we have learned new facts, that doesn't affect morality. At most it might affect how we apply the principles of that ancient book to our somewhat altered society, but not the basic ideas therein. Societal changes (principally the adoption of the welfare state in place of having children take care of their parents in old age) have rendered the basis of the bias against homosexuality suspect moot, but they haven't affected the issue of abortion much. Modern medicine allows us to use something a little less subjective than quickening can be used to demark the point at which a fetus becomes entitled to consideration under the law, but the basic reasons are still sound.
