Thanks, I've seen that before. What interested me about the reaction to it was every commentator decried them for suggesting babies should be killed, said that it would give weight to the arguments of anti-abortionists or that it showed how out of touch academics were with public opinion. But no-one gave an argument in response about why an 8 month abortion and a born baby are different in a morally relevant way. I had underestimated how much in general public discourse even discussing a morally condemned act was itself condemned.

In the context of slippery slopes, again this is moving between two adjacent points not showing you can just as easily move to any point on the scale.