Friday, November 20, 2009

Love Is In The Air

For my students, a little fun with logic. Consider the following syllogism. Does the conclusion (3) follow from the premises (1, 2)?

1) Everyone loves a lover;
2) John loves Jane;
3) Therefore, everyone loves everyone.


  1. To me it'd seem that 3) everyone loves John, and that for 3) to be true by those premises, 2) would have to read "everyone loves Jane." Or..?

  2. There are some premises that are assumed. If John loves Jane, then John is a lover. If everyone loves a lover, then everyone loves John. If everyone loves John, then everyone is a lover. If everyone is a lover, then everyone loves everyone.

    Of course, this assumes that "love" means the same thing in each premise.