"One way of catching class attention is to ask what advice [medical] students would give when presented with the following family history. The father has syphilis, the mother tuberculosis; they have already had four children -- the first is blind, the second died, the third is deaf and dumb, and the fourth has tuberculosis. The mother is pregnant with her fifth child, and the parents are willing to have an abortion, should you so decide.- L. R. C. Agnew of the University of California School of Medicine at Los Angeles, quoted in "A gripping lesson on abortion," The Palo Alto Times, 27 September 1977.
Assuming there aren't too many Catholics in the class, you will usually find a majority in favor of abortion. You congratulate the class on their decision to abort -- and then you tell them they have just murdered Beethoven."
(HT: Ray Ortlund)